Electrode system for electrical stimulation

ABSTRACT

A system for electrically stimulating a user comprising: a first housing portion defining an array of openings; an array of permeable bodies with portions exposed through the array of openings and wetted with a solution that facilitates electrical coupling between the system and a body region of the user, wherein each permeable body has a cavity at a proximal portion and a distal portion and is configured to transmit the solution to the body region of the user; a substrate region defining an array of protrusions configured to support the array of permeable bodies and composed of a conductive polymer; and a set of conductors in communication with the substrate region and including a first conductor that provides a first subset of the array of permeable bodies with a first polarity and a second conductor that provides a second subset of the array of permeable bodies with a second polarity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/878,647, filed 8 Oct. 2015, which is a continuation-in-partapplication of U.S. application Ser. No. 14/470,683 filed 27 Aug. 2015,which claims the benefit of U.S. Provisional Application Ser. No.61/870,631, filed 27 Aug. 2013, U.S. Provisional Application Ser. No.61/870,640, filed 27 Aug. 2013, U.S. Provisional Application Ser. No.61/870,643 filed 27 Aug. 2013, U.S. Provisional Application Ser. No.61/870,653, filed 27 Aug. 2013, U.S. Provisional Application Ser. No.61/870,658, filed 27 Aug. 2013, U.S. Provisional Application Ser. No.61/870,665, filed 27 Aug. 2013, U.S. Provisional Application Ser. No.61/870,710, filed 27 Aug. 2013, U.S. Provisional Application Ser. No.61/870,713, filed 27 Aug. 2013, and U.S. Provisional Application Ser.No. 61/870,715, filed 27 Aug. 2013, which are each incorporated in itsentirety herein by this reference.

This application also claims priority to U.S. application Ser. No.14/878,647, filed 8 Oct. 2015 which claims the benefit of U.S.Provisional Application Ser. No. 62/061,273, filed 8 Oct. 2014, U.S.Provisional Application Ser. No. 62/093,326, filed 17 Dec. 2014, U.S.Provisional Application Ser. No. 62/127,708, filed 3 Mar. 2015, U.S.Provisional Application Ser. No. 62/139,899, filed 30 Mar. 2015, U.S.Provisional Application Ser. No. 62/139,975, filed 30 Mar. 2015, andU.S. Provisional Application Ser. No. 62/221,475, filed 21 Sep. 2015,which are each incorporated in its entirety herein by this reference.

TECHNICAL FIELD

This invention relates generally to the biosignals field, and morespecifically to a new and useful electrode system for electricalstimulation.

BACKGROUND

Electrode systems in the biosignals field are used to transmitelectrical signals to a subject, and can additionally or alternativelybe used to detect or measure biosignals from the subject. Currentelectrode systems for electrical stimulation and/or biosignal detectionare, however, insufficient for many reasons including inadequate contactbetween the subject and the electrode(s) of a system, non-robust contactbetween the subject and the electrode(s) of a system in providing properimpedance characteristics at an electrode-user body interface, subjectdiscomfort while using an electrode system, and/or limited use withinmultiple electrical simulation or biosignal detection paradigms.

Thus, there is a need in the biosignals field for a new and usefulelectrode system for electrical stimulation and biosignal detection.This invention provides such a new and useful system.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A and 1B depict schematics of an embodiment of a system forproviding electrical stimulation to a user;

FIGS. 2A-2C depict variations of an array of permeable bodies in anembodiment of a system for providing electrical stimulation to a user;

FIGS. 3A-3C depict variations of a portion of an embodiment of a systemfor providing electrical stimulation to a user;

FIG. 4A depicts a variation of a system for providing electricalstimulation to a user;

FIG. 4B depicts variations of a housing surface in an embodiment of asystem for providing electrical stimulation to a user;

FIGS. 5A-5E depict variations of an embodiment of a system for providingelectrical stimulation to a user;

FIGS. 6A-6C depict variations of an array of protrusions in anembodiment of a system for providing electrical stimulation to a user;

FIGS. 7A-7C depict a first example of portions of an embodiment a systemfor providing electrical stimulation to a user;

FIGS. 8A-8C depict a second example of portions of an embodiment of asystem for providing electrical stimulation to a user;

FIGS. 9A and 9B depict additional variations of portions of embodimentsof a system for providing electrical stimulation to a user;

FIGS. 10A and 10B depict additional portions of the first example of asystem for providing electrical stimulation to a user;

FIGS. 11A and 11B depict variations of a portion of a system forproviding electrical stimulation to a user;

FIGS. 12A and 12B depict variations of a protrusion configuration in asystem for providing electrical stimulation to a user;

FIG. 13 depicts a variation of a positioning module in a system forproviding electrical stimulation to a user;

FIGS. 14A-14B depicts an embodiment of a module for displacing a user'shair, in an embodiment of a system for providing electrical stimulationto a user;

FIGS. 15A-15B depict variations of a portion of a system for providingelectrical stimulation to a user;

FIGS. 16A-16D depict variations of a portion of a system for providingelectrical stimulation to a user;

FIG. 17 depicts a first example of a first variation of a portion of asystem for providing electrical stimulation to a user;

FIGS. 18A-18D depict examples of a second variation of a portion of asystem for providing electrical stimulation to a user;

FIGS. 19A-19D depict examples of a third variation of a portion of asystem for providing electrical stimulation to a user;

FIGS. 20A-20C depict examples of a fourth variation of a portion of asystem for providing electrical stimulation to a user; and

FIGS. 21A-21D depict embodiments of modules for gripping a user's hair,in embodiments of a system for providing electrical stimulation to auser.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of preferred embodiments of the invention isnot intended to limit the invention to these preferred embodiments, butrather to enable any person skilled in the art to make and use thisinvention.

1. System

As shown in FIGS. 1A and 1B, embodiments of a system 110 for providingelectrical stimulation to a user comprises: an array of permeable bodies110 configured to absorb and deliver a solution that facilitateselectrical coupling between the system and a body region of the user; ahousing 105 supporting the array of permeable bodies; an electronicssubsystem 150 configured to transmit stimulation to a body region of theuser by way of the array of permeable bodies; and a coupling subsystem160 comprising a first electrical coupling region 161 in electricalcommunication with the array of permeable bodies at an interior portionof the housing and a second electrical coupling region 162, configuredto couple the first electrical coupling region to the electronicssubsystem. In some variations, the system 100 can, however, omit one ormore aspects of the electronics subsystem 150 described below.

The system 100 functions to transmit electrical stimulation to a userand can additionally or alternatively function to detect biosignals fromthe user by providing a robust connection between the user and a set ofelectrode contacts. Furthermore, the system 100 preferably functions tointerface directly with the user in a non-invasive manner in order totransmit an electrical stimulus and/or detect a biosignal (e.g., passivesignal, induced response) from the user. However, the electrode system100 can alternatively interface with the user in an invasive manner(e.g., by including elements configured to penetrate skin of the user).

In embodiments, the system 100 can be configured to transmit electricalstimulation of a single form or of multiple forms. As such, in someexamples, the system 100 can be configured to transmit one or more of:transcranial electrical stimulation (TES) in the form of transcranialdirect current stimulation (tDCS), transcranial alternating currentstimulation (tACS), transcranial magnetic stimulation (TMS),transcranial random noise stimulation (tRNS, e.g., band-limited randomnoise stimulation), transcranial variable frequency stimulation (tVFS),band-limited stimulation transformed to increase RMS power whileminimizing transients and clipping (embodiments, variations, andexamples of which are described in U.S. App. No. 62/127,708), and anyother suitable form of TES. Furthermore, in any of the above examplesand variations, the system 100 can be configured to deliver stimulationas anodal stimulation and/or cathodal stimulation. In other examples,the electrical stimulation can additionally or alternatively compriseany other form of electrical stimulation configured to stimulate anyother suitable region of the user's body, with any suitable penetrationdepth, and/or any suitable tissue structure (e.g., neural,musculoskeletal). Furthermore, for some types of stimulation (e.g.,tACS) that use biphasic waveforms (i.e., waveforms having phases of bothpositive and negative polarity, whether these phases are symmetrical ornot), the electrodes may not strictly be characterized as anodes orcathodes but, rather, act as both at various times over the duration ofstimulation; thus, the description of electrodes herein as cathodes oranodes is not intended to limit the application of the system 100 toforms of stimulation where the electrodes may be strictly characterized.

In some variations, robust connection with the user provided by theelements (e.g., mechanical aspects) of system 100 additionally oralternatively apply to transmission of non-electrical modes ofstimulation. As such, the system 100 can additionally or alternativelybe configured to transmit non-electrical modes of stimulation (e.g.,ultrasound stimulation, optical stimulation) by using any appropriatetransducer or set of transducers in place of or in addition to electrodecontacts. For instance, one variation of the system 100 can be used toprovide ultrasound transducing elements at a desired body region of theuser, as facilitated by an array of protrusions configured to displaceobstacles to ultrasound stimulation at the body region of the user. Inthis variation, ultrasound transducing elements can be configured at anysuitable position along a length of a protrusion and/or at a distal endof a protrusion. Other variations can, however, be configured toincorporate any other element(s) for stimulating the user.

In some embodiments, the system 100 can additionally or alternatively beconfigured to detect biosignals from the user. In one example, thesystem 100 is configured to detect electroencephalograph (EEG) signals,which can be reflective of a cognitive state of the user. In otherexamples, the bioelectrical signals can additionally or alternativelyinclude any one or more of: magnetoencephalograph (MEG) signals,galvanic skin response (GSR) signals, electrooculograph (EOG) signals,electromyelograph (EMG) signals, and any other suitable biosignal of theuser. Other variations of the system 100 can be configured to detect anyother suitable signal from the user, such as optical signals related toblood flow.

1.1 System—Electrode Contact Assembly

The electrode contact assembly preferably comprises the array ofpermeable bodies 110 and the housing 105, which together function tofacilitate generation of a reliable and robust electrical connectionbetween the system 100 and a body region of the user. In one embodiment,the system 100 can include multiple electrode contact assemblies,wherein one or more of the electrode contact assemblies include at leastone anode region and at least one cathode region. In a first specificexample of this embodiment, the system 100 includes a first electrodecontact assembly 101 a configured to interface with a superior centralportion of the user's motor cortex as a “central” electrode unit, and asecond and third electrode contact assembly 102 a, 103 a configured tointerface with contralateral portions of the user's motor cortex as“side” electrode units, as shown in FIG. 1A. However, variations of thefirst specific example can have any other suitable configurationrelative to any other suitable body region of the user.

In another embodiment, the system 100 can include two electrode contactassemblies, including a first electrode contact assembly 101 b thatfunctions as an anode electrode and a second electrode contact assembly102 b that functions as a cathode electrode, wherein both the firstelectrode contact assembly imb and the second electrode contact assembly102 b are coupled to the electronics subsystem 150, as described infurther detail below and shown in FIG. 1B. However, variations of thesystem 100 with multiple electrode contact assemblies can have any othersuitable configuration of regions (i.e., across different electrodecontact assemblies, across a single electrode contact assembly)configured as anodes or cathodes.

In variations of the system 100 with multiple electrode contactassemblies, one electrode contact assembly can be configured tointerface with a first body region of the user and another electrodecontact assembly can be configured to interface with a second bodyregion of the user. Furthermore, in some variations, an electrodecontact assembly can additionally or alternatively be configured with aset of regions coupled to or multiplexed to the electronics subsystem150, such that each region in the set of regions is configured todeliver stimulation in a distinct and/or controllable manner (e.g., witha desired amount of electrical current or voltage), independent of theother regions in the set of regions. The system 100 can, however,comprise any suitable number of electrode contact assemblies arranged inany other suitable manner, some variations of which are also describedbelow.

1.1.1 Electrode Contact Assembly—Array of Permeable Bodies

The array of permeable bodies 110 functions to absorb and deliver asolution that facilitates electrical coupling between the system and abody region of the user. The body region is preferably a head region ofthe user, and in a specific example, is a region defined as a portion ofthe scalp of the user. As such, in the specific example, the array ofpermeable bodies is preferably configured to facilitate generation of anelectrical connection to stimulate the brain of the user, through theuser's hair, scalp, and skull. However, the body region of the user canalternatively be any other suitable region of the user's body (e.g., atorso region, a region of an extremity, a region of a limb, etc.) thatcan be treated with electrical stimulation by way of the array ofpermeable bodies 110, and/or that can transmit biosignals from the userfor detection by the system 100.

The array of permeable bodies 110 preferably functions as a wetelectrode contact that comprises a fluid-absorbing material configuredto provide an electrically conductive connection to a power source(e.g., of an electrical subsystem for providing stimulation anddetecting signals). The fluid-absorbing material preferably has auniform matrix, but can alternatively have a non-uniform matrix.Furthermore, the fluid-absorbing material preferably has a high degreeof wettability (e.g., as indicated by a low contact angle, as indicatedby hydrophilic behavior, etc.), but can alternatively be characterizedby any suitable wettability behavior. The fluid-absorbing material ispreferably composed of a polymeric material, but can additionally oralternatively be composed of any other suitable hydrophilic material.The fluid-absorbing material can also be composed of a material, such aspolyethylene, that is not highly wettable in its usual state but hasbeen made wettable by application of a surface treatment such as plasmaor corona treatment, by inclusion of a surfactant (e.g., a polysorbatesurfactant, such as Polysorbate-20, Polysorbate-40, etc.), and/or in anyother suitable manner. Furthermore, the material of the array ofpermeable bodies 110 is preferably non-brittle and can preferablyundergo at least some amount of elastic deformation, such thatsubstantially each of the array of permeable bodies 110 can complyagainst the body of the user during use, and then elastically recoveragainst deformation. As such the composition of the array of permeablebodies 110 preferably contributes to reusability of the electrode system100 (e.g., for up to 10 uses, for up to 30 uses, for up to 100 uses,etc.). However, the composition of the array of permeable bodies 110 canadditionally or alternatively contribute to disposability of the system(e.g., in breaking down in function once the electrode system 100 shouldno longer be used). For instance, the material of the array of permeablebodies 110 can be configured to controllably decompose (e.g., due totuning porosity, due to tuning polymer chemistry, etc.) or to visiblychange (e.g., by including a material that gradually changes color afterhaving first been exposed to air) or to visually indicate potentialdegradation in electrode performance (e.g., by including a material thatchanges color irreversibly after having reached a temperature of greaterthan 60 degrees Celsius) to promote disposing of a unit of the electrodesystem 100 once the unit should no longer be used. Also, the material ofthe array of permeable bodies 100 can additionally or alternatively beconfigured to signal when appropriate wetness is achieved (e.g., byinclusion of a material that changes color when wet). However, thematerial of the array of permeable bodies 110 can additionally oralternatively be configured to perform any other suitable function inrelation to interfacing with the user.

In some variations, the fluid absorbing material of the array ofpermeable bodies 110 can comprise any one or more of: a foam material, anonwoven or woven fiber material, a sintered porous material, a hydrogelmaterial (e.g., silicon hydrogel, hydroxyethyl methacrylate hydrogel,polyvinyl alcohol hydrogel, sodium polyacrylate hydrogel, etc.), ahydrogel material processed (e.g., seeded, coated, layered, etc.) withconducting elements (e.g., by mixing, by template forming, bydeposition, by printing, by electrospinning, etc.), natural sponge,synthetic sponge (e.g., cellulose sponge, polymer sponge), fabric (e.g.,woven material), fluid-permeable material (e.g., a permeable orsemipermeable membrane), and any other suitable fluid-absorbingmaterial. In one such variation, the fluid-absorbing material cancomprise a polymer material (e.g., an olefin polymer, apolypropylene-derived material, a polyethylene-derived material, etc.)processed with a solute at one stage that is extracted from the polymermatrix at a later stage to form a foam-like material of a substantiallyopen-cell nature that can elastically recover against deformation. Inspecific examples of this variation, the material can have one or moreof: a pore-size between 10 μm and 300 μm, a porosity between 60% and90%, a density between 0.1 and 0.4 g/cm³, a tensile strength between 200and 2500 kPa, a percent elongation between 120% and 600%, and an ASKER-CHardness between 7 and 55 or a Shore A harness between 45 and 60°. Inparticular, the material can have a pore size from 30-50 μm, a porosityfrom 63-65%, and a Shore A hardness from 50-55°. However, the materialof examples of this variation can additionally or alternatively have anyother suitable material properties.

In another variation, the fluid-absorbing material can comprise apolymer material combined with a foaming agent to form a foam-likematerial. In another variation, the fluid-absorbing material cancomprise a fibrous (e.g. woven fibrous, nonwoven fibrous) polymermaterial (e.g., nylon, polyester). In yet another variation, thefluid-absorbing material can comprise sintered porous plastic material.However, in other variations, the material can be processed in any othersuitable manner and/or composed of any other suitable material(s).Furthermore, variations of the permeable bodies can include permeablebodies having different regions with different material types. Forinstance, in one such example, a permeable body can comprise a hydrogelmaterial partially or wholly encapsulated in a water-permeable membrane(e.g., porous polyethylene, porous textile, etc.) that allows wetting ofthe permeable body in, but prevents bulk escape of the hydrogel materialinto hair of the user. Additionally or alternatively, the hydrogelmaterial can be processed with a binding agent (e.g., polyvinyl acetate,ethylene vinyl acetate) that allows the hydrogel to retain a certaindesired morphology. Thus, the fluid absorbing material preferablyprovides a wet contact point and prevents escape of the solution forelectrical coupling in an uncontrolled manner (e.g., as indicated byfluid leaking).

In some variations, the fluid-absorbing material of the array ofpermeable bodies 110 can be configured to undergo a morphological and/orgeometric change upon fluid absorption. In one such example, thefluid-absorbing material can be compression-dried or vacuum-dried andprovided in a dry, compressed state, allowing a permeable body iii ofthe array of permeable bodies 110 to be in a compressed state duringapplication of the electrode system 100 to a user, and can be expandedupon fluid absorption in a wet configuration, thereby facilitatingelectrical coupling with the user, providing greater electrode-to-tissuecontact area and/or a decrease in an electrical resistance of anelectrode-to-tissue interface, and/or enabling displacement of a barrier(e.g., hair) to electrical coupling. In another such example, thefluid-absorbing material can be a shape memory material that undergoes amorphological change (e.g., a reversible morphological change, or anirreversible morphological change) in transitioning between wet and drystates. In yet another example, the fluid-absorbing material can undergonon-uniform expansion upon transitioning from a dry to a wet state(e.g., by spatial distribution of pores, by size-distribution of pores,by shape memory behavior, etc.).

In the above variations and examples, the fluid absorbed by thefluid-absorbing material can comprise saline, an electrolyte solution,an electrode gel, water, or any other suitable fluid that facilitateselectrical coupling between the array of permeable bodies 110 and theuser. Furthermore, the fluid can be used to facilitate administration ofinvasive, as well as non-invasive electrical stimulation and/ordetection of biosignals from the user. Furthermore, the fluid-absorbingmaterial of the array of permeable bodies 110 can be treated for any oneor more of: biocompatibility (e.g., with a hypoallergenic agent),reusability (e.g., with an antibacterial agent or with an antimycoticagent), non-reusability (e.g., with an agent that promotes degradationin function of the fluid-absorbing material), sterilization, and anyother suitable attribute. In any of the above treatments, thetreatment(s) can be performed prior to, during, and/or after usage ofthe array of permeable bodies 110 by the user. Furthermore, the fluidcan contain an agent (e.g., lidocaine hydrochloride) suitable foriontophoretic delivery to the tissue, or the material of the array ofpermeable bodies 110 can be treated with an agent suitable foriontophoresis such that the agent is eluted from the permeable bodies110 and caused to pass into the tissue by electrical current. In thisvariation, the agent can be chosen to perform a therapeutic functionrelated to delivery of electrical stimulation (e.g. reduction ofundesired skin sensation associated with electrical stimulation), or anyother desired therapeutic function.

In one embodiment, the array of permeable bodies 110 can be processed(e.g., impregnated) with electrolyte; for example, by treating with anelectrolyte solution (e.g., an electrolyte solution such as 0.9% salinesolution) and then transitioning to a dried state with electrolytedistributed throughout. Then, prior to use, the user or another entitycan treat the array of permeable bodies 110 with water (e.g., byspraying, by dipping, etc.), thereby transitioning the array ofpermeable bodies 110 to a wet state with appropriate characteristics(e.g., in relation to impedance), for stimulation of the user. However,the array of permeable bodies 110 can be configured to be transitionedbetween any other suitable state(s) and/or processed in any othersuitable manner for use by the user.

The array of permeable bodies 110 is preferably arranged in a patternedarray, in coordination with features of the housing 105, as describedbelow; however, the array of permeable bodies 110 can alternatively bearranged in a non-patterned (e.g., irregular) array, in coordinationwith features of the housing 105. In one variation, as shown in FIG. 2A,the array of permeable bodies 110′ is arranged as a one-dimensionalarray, wherein each permeable body 111 in the array of permeable bodies110 is spaced apart from an adjacent permeable body by a space. Theone-dimensional array can define a linear pattern or a non-linearpattern, and can additionally or alternatively comprise curved portions.Furthermore, upon absorption of fluid, a permeable body in of the arrayof permeable bodies can be configured to contact an adjacent permeablebody (e.g., due to expansion upon fluid absorption), or can beconfigured to maintain a desired spacing with an adjacent permeablebody.

In another variation, the array of permeable bodies 110″ is arranged asa two-dimensional array, wherein each permeable body 111 in the array ofpermeable bodies 110 is spaced apart from an adjacent permeable body bya space. The two-dimensional array can define any one or more of: arectangular pattern, a polygonal pattern, a circular pattern, anellipsoidal pattern, an amorphous pattern, and any other suitablepattern. Furthermore, upon absorption of fluid, a permeable body in ofthe array of permeable bodies can be configured to contact an adjacentpermeable body (e.g., due to expansion upon fluid absorption), or can beconfigured to maintain a desired spacing with an adjacent permeablebody. In one example of this variation, as shown in FIG. 2B, the arrayof permeable bodies 110″ can be arranged as a rectangular grid, inanother example of this variation, as shown in FIG. 2C, the array ofpermeable bodies 110′″ can be arranged as a series of concentriccircles, and in yet another example of this variation, the array ofpermeable bodies 110 can be arranged in a closest packed array (e.g.,hexagonal closest packed array).

Each permeable body 111 in the array of permeable bodies 110 can have asubstantially uniform cross section along a length or height of thepermeable body 111, or can alternatively have a non-uniform crosssection. A non-uniform cross section, such as a cross-section providinga tapered tip region of the permeable body 111 can, for instance,facilitate penetration through hair of the user to promote formation ofa robust electrode-user interface. In examples, the cross-section of apermeable body transverse to a longitudinal axis of the permeable body111 can be polygonal (e.g., rectangular, triangular, etc.) ornon-polygonal (e.g., circular, ellipsoidal, amorphous, etc.).Furthermore, in examples, the cross-section of a permeable body along alongitudinal axis of the permeable body 111 can be tapered to facilitatecommunication with a body region of the user, can be non-tapered, or canhave any other suitable shape. Alternatively, a broad cross-sectionproviding a blunted tip region 12 a of the permeable body 111, anexample of which is shown in FIG. 3A, can facilitate displacement ofhair of the user while resisting bending at the tip of the permeablebody 111, enhancing comfort when the tip is in contact with the user,and/or enhancing the appearance of the permeable bodies. Furthermore, inthis example, a narrow base region of the permeable body 111 can promotelocalized bending at the base region, to increase contact between moredistal portions of the permeable body in and the body region of theuser. Furthermore, a wide base region of the permeable body 111 taperingto a narrow tip region of the permeable body 111 can promote smoothbending (as opposed to buckling) of the permeable body 111 when incontact with the body region of the user.

In a first variation, as shown in FIGS. 1A and 3B, a permeable body 111′of the array of permeable bodies 110 can have a circular cross sectiontransverse to a longitudinal axis of the permeable body 111′, and atapered cross section defining a blunt tip region parallel to alongitudinal axis of the permeable body 111′. As such, in the firstvariation, the permeable body 111′ can have a tapered distal portion 12that facilitates electrical coupling with scalp through hair of theuser. In the first variation, the permeable body 111′ further can have acavity 11 at a proximal portion configured to be supported by asubstrate region 50 of the electrode contact assembly, described infurther detail below. Alternative variations of the first variation can,however, omit a cavity 11 and be supported by the substrate region 50 ofthe system 100 in any other suitable manner. In an example of the firstvariation, as shown in FIG. 3B, a permeable body 111′ has a height of12.75 mm, a cross-sectional diameter of 4.3 mm at a proximal end of thepermeable body 111′. In the example, the permeable body 111′ has atapered distal portion 12 beginning 5.50 mm from the proximal end of thepermeable body 111′, which terminates at a blunted tip region with adiameter of 1.00 mm. The specific example further has an internal cavity11 with a depth of 10.50 mm from the proximal portion of the permeablebody 111′, with a cross-sectional diameter of 2.40 mm that tapers alongthe longitudinal axis, beginning 3.50 mm from the proximal end of thepermeable body 111′. However, variations of the specific example of thefirst variation can alternatively have any other suitable dimensions. Inanother specific example, the cross section of the permeable body 111 isrectangular with a height of approximately 5 mm and a width ofapproximately 2 mm, wherein the permeable body in has a length ofapproximately 45 mm. In another specific example, the cross section of apermeable body 111 is square with a width of approximately 2 mm and alength of approximately 2 mm, wherein the permeable body in has a heightof approximately 15 mm.

As such, one or more permeable bodies in the array of permeable bodies110 can have a cross section that is non-uniform along a length orheight of the permeable body in, wherein the cross section is polygonal,ellipsoidal, or of any other suitable morphology. Furthermore, apermeable body 111 in the array of permeable bodies 110 can additionallybe characterized by any suitable concavity (e.g., convex surface,concave surface) at a distal end of the permeable body 111 (e.g., an endof the permeable body interfacing with the user) in order to facilitatebypassing and/or penetration of a barrier to electrical coupling. Thearray of permeable bodies 110 furthermore preferably span a footprinthaving an area below 40 cm² in order to provide stimulation to a gyrusor similarly-sized region of the brain; however, the array of permeablebodies 110 can alternatively span any other suitable footprint. In oneexample, a distal end of a permeable body 111 can have a convex surface(e.g., upon fluid absorption, or prior to fluid absorption), in order tofacilitate passage of the permeable body 111 through a user's hair, andto increase a surface area of electrode-to-skin contact when the system100 is held firmly against the user's skin. Furthermore, in examples,the array of permeable bodies can span a footprint having an area of 4.4cm×6.4 cm to provide an area of stimulation of approximately 30 cm².

In some variations, two or more of the array of permeable bodies 110 canbe coupled together in some manner (e.g., physically coextensive, ofunitary construction), for instance, to facilitate manufacturing of thesystem 100. In one such variation, a subarray (e.g., row of bodies,column of bodies, one of a set of concentric ring of bodies, etc.) ofthe array of permeable bodies 110 can be coupled at proximal regions(i.e., base regions) of the permeable bodies, as shown in FIG. 3C, suchthat the array of permeable bodies 110 is configured as multiplesubarrays of conjoined permeable bodies, as opposed toindividual/separated permeable bodies. Furthermore, the configuration ofsubarrays of the array of permeable bodies 110 can correspond to anodeand/or cathode regions associated with the substrate region 50 of thesystem 100 and/or the electronics subsystem 150 of the system 100, asdescribed in further detail below.

In some variations, one or more of the array of permeable bodies 110,and/or a region of a permeable body 111 can be substituted with orsupplemented with another suitable conductive material. In one suchexample, a core region of a permeable body 111 can comprise asubstantially non-fluid absorbing conductive material, which issurrounded by fluid absorbing material. Variations of the core regionare further described below, in relation to the substrate region 50included in some embodiments of the system 100. In variations, anon-fluid absorbing conductive material can comprise any one or more of:a metal (e.g., gold, steel, platinum), a metal alloy (e.g., gold alloy,platinum alloy), a semiconductor (e.g., doped silicon, a carbon-basedsemiconductor), a conductive polymer (e.g., polyacetylene, polyphenylenevinylene, polythiophene, polyaniline, polyphenylene sulfide,polypyrrole), and any other suitable conductive material. Suchconductive materials can be configured to provide or facilitateelectrical conductivity without necessitating a solution (e.g., saline,electrolyte solution) for conduction; however, the conductive materialcan additionally be used with a solution or gel, in order to facilitateelectrical coupling.

In one such variation, as shown in FIG. 4A, a conductive material (e.g.,metal conductor formed into wires, conductor formed into conductivetraces) can be configured to provide electrical coupling between theelectronics subsystem 150 and an array of permeable bodies 110 (e.g., anarray of permeable bodies comprising a hydrogel material permeated witha conductive liquid or solution) situated at distal ends of an array ofprotrusions 120, wherein the conductive material is directly coupled tothe material of the array of permeable bodies 110, without relying onthe conductive liquid or solution, provided by a manifold 140, to carryelectrical current proximal to the array of permeable bodies 110. Inexamples of this variation, the conductive material can travel along aninternal and/or an external portion of the housing 105 to electricallycommunicate with permeable bodies positioned at distal portions of thearray of protrusions (e.g., as described in further detail below inrelation to the substrate region so), in order to provide electricalcoupling between the array of permeable bodies 110 and the electronicssubsystem 150 of the system 100. As such, some variations of the system100 can omit a manifold 140 and provide direct coupling betweenpermeable bodies of an array of protrusions and the electronicssubsystem 150 using one or more conductive materials.

In one example of this variation, the system 100 can include an array ofconductive traces coupled between the electronics subsystem 150 and eachof the array of permeable bodies 110 (e.g., by way of the couplingsubsystem 160, wherein each of the array of permeable bodies 110 ispermeated (e.g., pre-saturated) or is configured to be permeated (e.g.,via the user applying fluid to the permeable bodies before use) with anelectrical coupling fluid configured to facilitate transmission of theelectrical stimulation treatment to the user. In the example, eachconductive trace is paired with a permeable body in a one-to-one manner;however, variations of the example can include coupling between thearray of permeable bodies and the array of conductive traces in aless-than-one-to-one or a more-than-one-to-one manner. In more detail,in a specific example the conductive material can comprise anelastomeric material (e.g., molded silicone rubber elastomer) containingor otherwise doped with a conductive substance (e.g., carbon blackparticles). Such a composition can function to control electrochemicalreaction products that would otherwise result with use of othermaterials (e.g., metal) for the junction between “electronic” conductionand “ionic” conduction. Furthermore, such a composition can be readilyconfigured to conform morphologically with the morphology of the arrayof permeable bodies 110, as described in more detail below.Additionally, elastic properties of this material composition canfacilitate a press-fit interface against metal to ensure reliablecontact. Furthermore, such a composition can ensure good, but slightlyless than perfect conductivity (e.g., with volume resistivity of ˜2 to50 Ohm-cm), which can provide a desired amount of current distribution.In more detail, if the path to each of the array of permeable bodies 110has some resistance (e.g., a low amount of resistance in comparison tothe tissue resistance), it is more likely that each of the array ofpermeable bodies 110 will receive some current even in the presence ofvariation in quality of contact between the permeable bodies and theuser. However, any other suitable material (e.g., metallic conductor,rubber doped with metal, etc.) can be used, and the array of permeablebodies 110 can alternatively be configured to couple to the electronicssubsystem 150 in any other suitable manner.

1.1.2 Electrode Contact Assembly—First Embodiment of the Housing andArray of Protrusions of the Substrate Region

The housing 105 functions to convey the array of permeable bodies 110 tothe body region of the user and to facilitate electrical couplingbetween the electronics subsystem 150 (described in more detail below)and the body region of the user. In one embodiment, as shown in FIGS. 1Aand 5A-5D, the housing 105 a can include a first housing portion 5 and asecond housing portion 6, however, some variations of this embodimenthousing 105 can additionally or alternatively omit either portion of thehousing 105. For instance, in one such variation of this embodiment ofthe housing 105, the housing 105 can only include a second housingportion 6 that supports the substrate region 50 and array of permeablebodies 110. The first housing portion 5 in this embodiment preferablydefines an array of openings 7 at a broad surface 8, wherein the arrayof openings 7 exposes distal portions of the array of permeable bodies110 for interfacing with the body region of the user during use. Thebroad surface 8 of the first housing portion 5 is preferably anon-planar surface that is complementary to the body region of the userintended to be stimulated by the system 100; however, the broad surface8 can alternatively be a planar surface (or any other suitable surface),such that at least one of 1) the broad surface 8 of the first housingportion 5 and, 2) collectively, distal portions of the array ofpermeable bodies 110 define a surface that is complementary to the bodyregion of the user during use of the system 100.

The second housing portion 6 is preferably configured to couple to thefirst housing portion 5 to define a volume within which the substrateregion 50 and the set of conductors 60 of the coupling subsystem 160(described in more detail below) are sealed or otherwise protected fromdamage. In particular, as shown in FIG. 5A, portions of the substrateregion 50 that interface with pads 62 (described in more detail below)can serve as the set of conductors 60. Furthermore, as described in moredetail below, at least one of the first housing portion 5 and the secondhousing portion 6 can function to facilitate electromechanical couplingof conductive portions of the substrate region 50 and/or the set ofconductors 60 to the electronics subsystem 150, for transmission ofelectrical stimulation through the array of permeable bodies 110 to theuser.

The housing 105 a is preferably composed of a rigid material (e.g., arigid plastic material, etc.), such that the housing 105 a does notdeform in response to normal forces, shear stresses, bending stresses,or torsional stresses induced during use of the system 100.Alternatively, the housing 105 a can be flexible to facilitatemaintenance of compliance with a body region of the user (e.g., as theuser performs a physical activity while the system 100 is coupled to theuser). In variations wherein the housing 105 a is flexible, otherelements of the system 100 can also be flexible (e.g., the electronicssubsystem 150 can comprise a flexible thin film battery, the electronicssubsystem 150 can comprise flexible electronics, the electronicssubstrate 64 can comprise a flexible printed circuit board, etc.) tofacilitate compliance with the body region of the user. In specificexamples, the housing 105 a can be composed of one or more of: apolycarbonate-derived material, an acyrlonitrile butadiene styrene(ABS)-derived material, and any other suitable material.

The housing 105 a preferably has a profile that does not protrude asignificant distance from the body region of the user when the user isbeing stimulated by the system 100. As such, the housing 105 apreferably has a low aspect ratio that contributes to a thin form factorof the system 100. However, the housing 105 a can alternatively define avolume with a high aspect ratio. Preferably, the external surface of thehousing 105 a is substantially smooth and has rounded edges, in order toavoid discomforting or injuring the user as the user interfaces with thesystem 100.

Furthermore, the housing 105 a can define a substantially polygonalfootprint (i.e., a quadrilateral footprint, a triangular footprint, apentagonal footprint, a hexagonal footprint, etc.), or can alternativelydefine one or more of a circular footprint, an ellipsoidal footprint,and an amorphous footprint. In one example, as shown in FIG. 5A, thehousing 105 a defines a rectangular footprint and has a thicknesssubstantially below 2 cm, a length below 15 cm, and a width below 10 cm,in order to produce a form factor with a low aspect ratio and sufficientsurface area to facilitate stimulation of the user. Variations of theexample of the housing 105 a can, however, be configured in any othersuitable manner.

As described briefly above, the housing 105 a preferably forms a shellabout its internal components, and preferably has a first housingportion 5 facing the body region of the user when the system 100interfaces with the user and a second housing portion 6 facing away fromthe body region of the user when the system 100 interfaces with theuser. The first housing portion 5 and the second housing portion 6 canbe coupled together (e.g., using a hermetic sealing element) using oneor more of: a snap fit, a mechanical press fit, a thermal bond, anadhesive, a compliant sealing material (e.g., putty), an o-ring, anx-ring, any other suitable ring, and/or any other suitable sealingelement. As such, an interface between the first housing portion 5 andthe second housing portion 6 can be configured to be waterproof in orderto protect elements internal to the housing 105 a, and/or can beconfigured to protect internal elements of the housing 105 a in anyother suitable manner. Alternatively, an interface between the firsthousing portion 5 and the second housing portion 6 can be configured tonot be waterproof and, as stated above, some variations of thisembodiment of the housing 105 can omit the first housing portion 5.

As described briefly above, the housing 105 a preferably has an array ofopenings 7 defined at the first housing portion 5, wherein the array ofopenings 7 exposes distal portions of the array of permeable bodies 110for interfacing with the body region of the user during use. Preferably,the array of openings 7 is defined entirely at the first housing portion5; however, in alternative variations, the array of openings 7 can bedefined at both the first housing portion 5 and the second housingportion 6, or at only the second housing portion 6. The array ofopenings 7 can be a rectangular array of openings 7; however, the arrayof openings 7 can alternatively be configured in any other suitablemanner (e.g., as a circular array of openings, as an ellipsoidal arrayof openings, as a polygonal array of openings, as an amorphous array ofopenings, etc.). Each opening in the array of openings 7 is alsopreferably a circular opening, but can alternatively be a non-circularopening (e.g., in complementing an external surface of a permeable bodyof the array of permeable bodies). Furthermore, each opening in thearray of openings 7 is preferably identical to every other opening inthe array of openings 7 in morphology; however, the array of openings 7can alternatively comprise non-identical openings. In a specificexample, as shown in FIGS. 5A-5D the array of openings 7 includes 24identical circular openings arranged in a 4×6 rectangular array, eachopening having a diameter of 4.30 mm and an inter-opening spacing ofthat prevents contact between adjacent permeable bodies in theirundeformed state and minimizes overlap between adjacent permeable bodieswhen they are deformed in contact with the user; however, variations ofthe specific example of the array of openings 7 can be configured in anyother suitable array.

In some variations, as shown in FIG. 5E, a base region 9 of each openingof the array of openings 7 of the housing 105 a can be recessed at thebroad surface 8 facing the user, in order to facilitate retention ofexcess fluid at the housing 105 a, in a controlled manner, during use ofthe system 100 by the user. For instance, in example scenarios where theuser dips the array of permeable bodies 110 in water prior to use, orsprays the array of permeable bodies 110 with water prior to use,recesses at the base regions 9 of the array of openings 7 of the housingcan help guide fluid to and/or retain fluid proximal the array ofpermeable bodies 110, such that they are properly saturated prior to useby a user. In one variation, the base region 9 of each opening of thearray of openings 7 of the housing 105 a can be concave, and in aspecific example, the base region 9 of each opening can be a concentricbowl about its corresponding opening. In alternative variations, therecessed base region 9 can have any other suitable morphology (e.g.,conical, pyramidal, step-wise, etc.).

Additionally or alternatively, portions of the base regions 9 of one ormore openings of the array of openings 7 can additionally oralternatively protrude from (e.g., have a convex portion at) the housing105, in order to support proximal portions of the array of permeablebodies 110. For instance, a protruding base region 9 can provideadditional mechanical support to a permeable body 111, thereby providinga bending constraint at the base region 9.

While one embodiment of the housing 105 a of the system 100 is describedabove, alternative embodiments of the housing 105 a can be configured inany other suitable manner, one such embodiment of which is describedbelow in Section 1.1.3.

As shown in FIGS. 1A and 5A, the first embodiment of the housing 105 apreferably supports a substrate region 50, which functions to conductcurrent for electrically stimulating the user, to the array of permeablebodies 110. The substrate region 50 is thus preferably composed of aconductive material (e.g., metal, semiconductor, polymer, etc.);however, the substrate region 50 can additionally or alternatively becomposed of an insulating material with conductive traces that transmitcurrent from the electronics subsystem 150 through the conductive tracesof the substrate region 50 to the array of permeable bodies 110, or amaterial such as silicone rubber that is not intrinsically conductivebut is made conductive by inclusion of a conductive material such ascarbon. The substrate region 50 can have some flexibility in relation tosupporting the array of permeable bodies 110, such that the array ofpermeable bodies 110 can flex, with at least a portion of the substrateregion 50, to conform to the body region of the user. However, thesubstrate region 50 can alternatively exhibit a higher degree ofrigidity in supporting the array of permeable bodies 110. In onevariation, the substrate region 50 is composed of a conductive polymercomposition (e.g., polypyrrole, non-conductive polymer with adistribution of conductive components, silicone rubber made conductiveby inclusion of carbon, etc.) that supports the array of permeablebodies 110. However, the substrate region 50 can alternatively becomposed of a non-polymeric material.

In supporting the array of permeable bodies 110, the substrate region 50is preferably coupled to the array of permeable bodies 110, such thatthe substrate region 50 is in physical communication with the array ofpermeable bodies 110 and thus, in electrical communication with anelectrolyte solution absorbed by or contained within the array ofpermeable bodies 110. In coupling to the array of permeable bodies 110,the substrate region 50 can be removably coupled or alternatively,permanently coupled to the array of permeable bodies 110 using one ormore of: an adhesive coupling mechanism, a mechanical couplingmechanism, a thermal coupling mechanism, a magnetic coupling mechanism,and any other suitable coupling mechanism. In one such variation, asshown in FIG. 5A, the substrate region 50 can define an array ofprotrusions 120 a that support the array of permeable bodies 110. Inmore detail, and in relation to a variation of the array of permeablebodies 110 described in Section 1.1.1 above, the array of protrusions120 a can correspond to and be configured to reside within cavities 11of the array of permeable bodies 110, such that each permeable bodyforms a sleeve around a corresponding protrusion of the array ofprotrusions 120 a. However, the array of protrusions 120 a of thesubstrate region 50 can additionally or alternatively cooperate with thearray of permeable bodies 110 in any other suitable manner, such thatthe array of protrusions 120 a corresponds to and supports the array ofpermeable bodies 110.

In more detail, the array of protrusions 120 a can function, with thearray of permeable bodies, to facilitate bypassing and/or penetration ofbarriers to electrical coupling, such that the system 100 can robustlyinterface with a body region of the user. Preferably, the array ofprotrusions 120 a is configured to bypass the user's body hair; however,the array of protrusions can additionally or alternatively be configuredto facilitate bypassing or penetration of any other barrier toelectrical coupling (e.g., clothing, fur). The array of protrusions 120a is preferably configured to not penetrate the user's body, such thatthe system 100 is substantially non-invasive; however, the array ofprotrusions 120 a can alternatively be geometrically configured topenetrate or abrade the stratum corneum of the user and/or anyunderlying tissue structure, such that the system 100 is configured tobe invasive or minimally invasive. The array of protrusions 120 a, incooperation with the array of permeable bodies 110 preferably provides aregion of contact between a body region of the user and the system 100,in order to facilitate electrical coupling. Furthermore, each protrusion121 a in the array of protrusions 120 is preferably associated with apermeable body in of the array of permeable bodies 110 in a one-to-onemanner; however, the array of protrusions 120 and the array of permeablebodies 110 can alternatively be associated in a many-to-one manner or aless-than-one-to-one manner.

The array of protrusions 120 a, in its entirety, is thus preferablygeometrically configured to bypass or penetrate a barrier, for example,by spatial arrangement and/or distribution of protrusions 121 a in thearray of protrusions 120 a. Similar to the array of permeable bodies110, in one variation, the array of protrusions 120 a′ can be a lineararray, in a manner analogous to the example shown in FIG. 2A, or can bea multi-dimensional array of protrusions 120 a″, 120 a′″ in mannersanalogous to examples shown in FIGS. 2B and 2C. All protrusions in thearray of protrusions 120 a can additionally be substantially identicalto each other, or can be non-identical to each other in order tofacilitate conformation to the user and/or to provide robust electricalcoupling. For example, the protrusions in the array of protrusions 120 acan be characterized by one or more of: different heights, differentwidths, different diameters, different cross-sectional profiles,different material compositions, different mechanical behavior,different electrical behavior, any other suitable property difference,and any suitable combination of property differences. Preferably, theheight of each protrusion in the array of protrusions 120 a is greaterthan the thickness of the barrier (e.g., a user's hair) duringapplication of the system 100 to the user. However, in other variations,only a subset of protrusions in the array of protrusions 120 a can havea height greater than the thickness of a barrier to electrical coupling,or no protrusion in the array of protrusions 120 a is characterized by aheight greater than the thickness of a barrier to electrical coupling.Furthermore, the array of protrusions 120 a can be configured to definea non-continuous surface that forms a complementary surface to a surfaceof the user, by comprising protrusions of varying or variable lengths.Alternatively, and similar to the housing 105 a, the array ofprotrusions 120 a can be arranged at a non-planar surface of thesubstrate region 50 in order to complement a surface of the body regionof the user. In one example, the array of protrusions 120 a can beconfigured, with a non-planar surface of the substrate region 50, todefine a concave surface that is complementary to a convex surface ofthe user's body (e.g., skull). However, the array of protrusions 120 acan alternatively collectively define any other suitable surface.

Each protrusion 121 a in the array of protrusions 120 a can additionallyor alternatively be configured to individually facilitate barrierbypassing and/or penetration. Preferably, each protrusion 121 isgeometrically configured to facilitate barrier bypassing and/orpenetration; however, any protrusion in the set of protrusions no can beconfigured to facilitate barrier bypassing and/or penetration in anyother suitable manner. In one variation, at least one protrusion 121 inthe set of protrusions 120 is characterized by a cross-sectional profiletapering continuously to at least one point 122 a, as shown in FIG. 5A,wherein the point(s) 122 can be blunted or shielded in order to preventpenetration of the user's body. In one example of this variation, aprotrusion 121 a can be configured to taper in a direction perpendicularto the scalp of the user (e.g., in a proximal-to-distal direction), uponapplication of the system 100 to the user, such that the point 122 a ofthe protrusion 121 a is oriented normal to the scalp of the user. Assuch, the protrusion(s) 121 a of the array of protrusions 120 a can beconfigured to extend laterally from the substrate region 50, an exampleof which is shown in FIG. 5A. In alternative variations, protrusions ofthe array of protrusions 120 a can be configured in any suitableorientation that facilitates delivery of distal ends of the protrusionsto a scalp region of the user in any other suitable manner. Forinstance, protrusions extending from a substrate in an angled, whorled,and/or spiraled configuration (e.g., extending in a manner that is notdirectly perpendicular to the substrate) can provide a mechanism wherebythe protrusions “screw” into position at the user's scalp.

At least one protrusion 121 a of the array of protrusions 120 a can bedeflectable and/or deformable (e.g., elastically, plastically) in orderto further enhance electrical coupling between the system 100 and theuser. In one variation, a protrusion of the array of protrusions 110 canbe configured to deflect laterally (e.g., based upon morphology, basedupon inclusion of a joint at a portion of the protrusion), based uponinclusion of a hinge at a portion of the protrusion), such thatapplication of the array of protrusions 110 at the user, along withlateral deflection of a protrusion during application (e.g., by applyingpressure normal to a surface of the housing 105 a and/or laterallymoving the housing 105 a during application of the system 100 to theuser), facilitates contact between the system 100 and the user.Alternatively, at least a portion of a protrusion 121 a can beconfigured to be substantially rigid, thus allowing no deflection ordeformation (with deflection enabled by other regions of the substrateregion 50). As such, a protrusion 121 can be characterized by anysuitable combination of variations, or any other suitable variation.Furthermore, a protrusion 121 a of the array of protrusions 120 a can besubstantially solid, or can define a hollow region in order tofacilitate electrical coupling (e.g., for providing a pathway for anelectrical connection, for delivering a fluid to the protrusion tofacilitate deflection and/or expansion of a permeable body).

In a specific example, as shown in FIGS. 5A-5D, the array of protrusions120 a comprises 24 protrusions arranged in a 4×6 array, corresponding toan example of the array of permeable bodies 110; however, the array ofprotrusions 120 a can alternatively comprise any other suitableconfiguration.

In some variations, one of which is shown in FIG. 5A, the substrateregion 50 can be separated into a set of subregions 53, in relation tovariations of the system 100 wherein different subsets of the array ofpermeable bodies 110 are configured to have different electricalstimulation parameters (e.g., different polarities, different currentlevels, different impedance levels, different operational states, etc.).For instance, a first subregion 53 a of the substrate region 50 can beconfigured to have a first polarity (e.g., to function as an anode), anda second subregion 53 b of the substrate region 50 that is separated orotherwise isolated from the first subregion 53 a can be configured tohave a second polarity (e.g., to function as an anode), upon couplingthe substrate region 50 to a set of conductors 60 of a first electricalcoupling region 161 of the coupling subsystem 160 (described in furtherdetail below). The subregions 53 a, 53 b can be isolated from each otherusing one or more of: a spacing element positioned between thesubregions 53 a, 53 b, an insulating material element positioned betweenthe subregions 53 a, 53 b, a space between element the subregions 53 a,53 b, and in any other suitable manner.

In a specific example, as shown in FIG. 5A, the substrate region isdivided into a first subregion 53 a with a first subset of protrusionsconfigured to have a first polarity, and a second subregion 53 b and athird subregion 53 c with a second subset of protrusions and a thirdsubset of protrusions, respectively, each of the second and the thirdsubregions 53 b, 53 c configured to have a second polarity. As shown inFIGS. 5A-5D, the first, the second, and the third subregions 53 a, 53 b,and 53 c each have rectangular footprints, and the second and the thirdsubregions 53 b, 53 c each flank an opposing side of the first subregion53 a. In the specific example, in the first region 53 a comprises 12protrusions arranged in a 2×6 rectangular array, and each of the secondand the third subregions 53 b, 53 c each comprise 6 protrusions arrangedin a 1×6 linear array. Furthermore, to prevent shorting of thesubregions 53 a, 53 b, 53 c, the first subregion 53 a is separated fromboth the second subregion 53 b and the third subregion 53 c by a set ofspacers 54 (e.g., 2 insulating spacers), such that contact between thesubregions 53 a, 53 b, 53 c is prevented. Alternatively, the spacers 54can be substituted with any other suitable insulator (e.g., air) toprevent undesired contact between the subregions 53 a, 53 b, 53 c.Furthermore, variations of this specific example can alternatively bearranged in any other suitable manner.

1.1.3 Electrode Contact Assembly—Second Embodiment of the Housing, Arrayof Protrusions, and Manifold

In another embodiment, as shown in FIG. 1B, the housing 105 can definean array of protrusions 120 and comprise one or more of: an array ofchannels 130 distributed across the array of protrusions, each channel131 in the array of channels surrounding a permeable body of the arrayof permeable bodies 110 and configured to deliver the solution to thepermeable body, and a manifold 140 configured to distribute the solutionto the array of channels 130. In some variations, one or more channels131 of the housing 105 b can comprise or be coupled to a barrier 142configured to prevent passage of a permeable body 111 past the barrierin a distal-to-proximal direction (e.g., in a direction into the housingor away from the body of the user). The housing 105 b thus functions toconvey the array of permeable bodies 110 to the body region of the user,to facilitate distribution of fluid to the array of permeable bodies,and to facilitate electrical coupling between an electronics subsystem150 and the body region of the user.

The housing 105 b of this embodiment preferably serves as a substratethat functions to form a core or base structure to which other elementsof the system 100 can be coupled and/or otherwise placed incommunication (e.g., electrical communication). Preferably, the housing105 b is physically coextensive with the array of protrusions 120;however, the housing 105 b can alternatively be of unitary constructionwith the array of protrusions 120, or can couple to the array ofprotrusions 120 using any suitable bonding method (e.g., thermalbonding, adhesive bonding, electrical bonding). In still othervariations, the housing 1O5 b can be configured to couple to the arrayof protrusions 120 in a manner that allows one or more protrusions ofthe array of protrusions 120 to have adjustable depths within thehousing 105 b (e.g., in order to be in communication with subsets ofchannels of the housing). In some variations, the housing 105 b can beflexible, such that the array of protrusions 120 and/or the housing 105b is configured to flexibly conform to the user's body. In othervariations, however, the housing can be entirely rigid, or canadditionally or alternatively comprise portions that are substantiallyrigid. In variations wherein the housing 105 b is rigid, the housing 105b can define a planar surface 106, as shown in FIG. 4B (left),configured to interface with the body region of the user, such thatother elements (e.g., the array of protrusions 120) enable aconfiguration that conforms to the user, or the housing 105 b can definea non-planar surface 106′, as shown in FIG. 4B (right), that facilitatesconformation of the system 100 to a body region of the user. In one suchexample, the housing 105 b can include a concave surface 106′ that iscomplementary to a head region of the user, such that the housingconforms to the user's head region. In still other variations, thehousing 105 b can be flexible in one environment and rigid in anotherenvironment (e.g., the substrate is a shape memory material), such thatthe housing 105 b is characterized by different mechanical behavior indifferent environments. For example, the housing 105 b can comprise ashape memory metal or polymer that is configured to be planar when thesystem 100 is not coupled to the user, and configured to conform to theuser when the system 100 is coupled to the user. In variations whereinthe housing 105 b can undergo a rigid-to-flexible transition or aflexible-to-rigid transition, the transition can be reversible ornon-reversible.

In variations, the housing 105 b can comprise one or more of: anon-conductive material (e.g., plastic, polyethylene, ABS, polyethylethyl ketone, polyurethane, rubber, ceramic, etc.) and a conductivematerial (e.g., metal, stainless steel, etc.). However, the housing 105b can additionally or alternatively comprise any other suitablematerial(s).

The array of protrusions 120 functions to facilitate bypassing and/orpenetration of barriers to electrical coupling, such that the system 100can robustly interface with a body region of the user. Preferably, thearray of protrusions 120 is configured to bypass the user's body hair;however, the array of protrusions can additionally or alternatively beconfigured to facilitate bypassing or penetration of any other barrierto electrical coupling (e.g., clothing, fur). The array of protrusionsis preferably configured to not penetrate the user's body, such that thesystem 100 is substantially non-invasive; however, the array ofprotrusions can alternatively be geometrically configured to penetrateor abrade the stratum corneum of the user and/or any underlying tissuestructure, such that the system 100 is configured to be invasive orminimally invasive. The array of protrusions 120, in cooperation withthe array of permeable bodies 110 preferably provides a region ofcontact between a body region of the user and the system 100, in orderto facilitate electrical coupling. Furthermore, each protrusion 121 inthe array of protrusions 120 is preferably associated with a permeablebody in of the array of permeable bodies 110 in a one-to-one manner;however, the array of protrusions 120 and the array of permeable bodies110 can alternatively be associated in a many-to-one manner or aless-than-one-to-one manner. The array of protrusions 120 can beconfigured with an inter-protrusion spacing that facilitates delivery ofa substantially uniform density of electrical current to the body regionof the user during use, and in examples, an inter-protrusion spacing canbe between 5 and 20 mm.

The array of protrusions 120, in its entirety, is thus preferablygeometrically configured to bypass or penetrate a barrier, for example,by spatial arrangement and/or distribution of protrusions 121 in thearray of protrusions 120. Similar to the array of permeable bodies 110,in one variation, the array of protrusions 120′ can be a linear array,an example of which is shown in FIG. 6A, or can be a multi-dimensionalarray of protrusions 120″, an example of which is shown in FIG. 6B. Allprotrusions in the array of protrusions 120 can additionally besubstantially identical to each other, or can be non-identical to eachother in order to facilitate conformation to the user and/or to providerobust electrical coupling. For example, the protrusions in the array ofprotrusions 120 can be characterized by different heights, differentwidths, different diameters, different cross-sectional profiles,different material compositions, different mechanical behavior,different electrical behavior, any other suitable property difference,and/or any suitable combination of property differences. Preferably, theheight of each protrusion in the array of protrusions 120 is greaterthan the thickness of the barrier (e.g., a user's hair) duringapplication of the system 100 to the user. However, in other variations,only a subset of protrusions in the array of protrusions 120 can have aheight greater than the thickness of a barrier to electrical coupling,or no protrusion in the array of protrusions 120 is characterized by aheight greater than the thickness of a barrier to electrical coupling.Furthermore, the array of protrusions 120 can be configured to define anon-continuous surface that forms a complementary surface to a surfaceof the user, by comprising protrusions of varying or variable lengths.In one example, the array of protrusions 110 can be configured to definea concave surface that is complementary to a convex surface of theuser's body (e.g., skull).

Each protrusion 121 in the array of protrusions 120 can additionally oralternatively be configured to individually facilitate barrier bypassingand/or penetration. Preferably, each protrusion 121 is geometricallyconfigured to facilitate barrier bypassing and/or penetration; however,any protrusion in the set of protrusions 110 can be configured tofacilitate barrier bypassing and/or penetration in any other suitablemanner. In one variation, at least one protrusion 121 in the set ofprotrusions 120 is characterized by a cross-sectional profile taperingcontinuously to at least one point 122, as shown in FIG. 1B, wherein thepoint(s) 122 can be blunted or shielded in order to prevent penetrationof the user's body. In a first example of this variation, a protrusion121 can be configured to taper in a direction tangential to the scalp ofthe user, upon application of the system 100 to the user, such that thepoint 122 of the protrusion 121 facilitates combing of the protrusion121 through the user's hair in a tangential direction. In a secondexample of this variation, a protrusion 121 can be configured to taperin a direction perpendicular to the scalp of the user (e.g., in aproximal-to-distal direction), upon application of the system 100 to theuser, such that the point 122 of the protrusion 121 is oriented normalto the scalp of the user. As such, the protrusion(s) 121 of the array ofprotrusions 120 can be configured to extend laterally from a substratedefined by the housing 105, an example of which is shown in FIG. 6A,and/or to extend perpendicularly from a substrate defined by the housing105, an example of which is shown in FIG. 6B. In alternative variations,protrusions of the array of protrusions 120 can be configured in anysuitable orientation that facilitates delivery of distal ends of theprotrusions to a scalp region of the user in any other suitable manner.For instance, protrusions extending from a substrate in an angled,whorled, and/or spiraled configuration (e.g., extending in a manner thatis not directly perpendicular to the substrate) can provide a mechanismwhereby the protrusions “screw” into position at the user's scalp. Inone such specific example, the protrusions can extend from the substratein a manner whereby a geometric projection of each protrusion onto theplane of the substrate is approximately tangential to one of a set ofcircles (e.g., concentric circles, non-concentric circles). Additionallyor alternatively, base regions of the array of protrusions 120 thatinterface with the broad surface of the housing 105 b can be one or moreof: chamfered, rounded, or beveled to reduce stress concentrationfactors at protrusion-housing interfaces.

A protrusion 121 can further be defined by a rotational axis of symmetry(e.g., as in a conical, screw, auger, or barb-tipped protrusion) about alongitudinal axis, a single axis of symmetry, multiple axes of symmetry(e.g., as in a pyramidal or prismatic protrusion), or any other suitablesymmetry or asymmetry. Furthermore, a protrusion 121 can becharacterized by a cross-sectional profile (e.g., profile transverse toa longitudinal axis) with straight or curved edges (e.g., in anon-circular manner, in an ellipsoidal manner, etc.), an example ofwhich is shown in FIG. 6C, and can additionally or alternatively definea non-planar surface configured to conform to a suitable surface of theuser (e.g., at a region of contact for an electrode contact). Forexample, a protrusion 121 can comprise a concave surface (e.g.,extending laterally from the housing, extending perpendicularly from thehousing), which, along with a permeable body, facilitates coupling to aconvex portion of a user's body (e.g., skull). In another example, aprotrusion 121 can comprise a convex surface, which, along with apermeable body, facilitates coupling to a concave portion of a user'sbody. Furthermore, any protrusion 121 in the array of protrusions cancomprise a feature at any suitable portion of the protrusion 121 (e.g.,a wedge shaped profile at a distal end of the protrusion) configured todeflect a barrier to electrical coupling (e.g., hair).

At least one protrusion 121 can be deflectable and/or deformable (e.g.,elastically, plastically) in order to further enhance electricalcoupling between the system 100 and the user. In one variation, aprotrusion of the array of protrusions 110 can be configured to deflectlaterally, such that application of the array of protrusions no at theuser, along with lateral deflection of a protrusion during application(e.g., by applying pressure normal to a surface of the housing 105 band/or laterally moving the housing 105 b during application of thesystem 100 to the user), facilitates contact between the system 100 andthe user. In another variation, a protrusion 121 can be configured tooutwardly expand, thus laterally displacing a barrier to electricalcoupling or a portion of a barrier to electrical coupling, in order tofacilitate application of the system 100 to the user. In examples ofthis variation, the protrusion 121 can be configured to expand upon anyone or more of: absorption of a fluid, infilling by a liquid or gas,transfer to a different environment (e.g., as in a shape memorymaterial), mechanical deformation or actuation, and any other suitablemechanism of expansion. Alternatively, at least a portion of aprotrusion 121 can be configured to be substantially rigid, thusallowing no deflection or deformation. As such, a protrusion 121 can becharacterized by any suitable combination of variations, or any othersuitable variation. Furthermore, a protrusion 121 of the array ofprotrusions 120 can be substantially solid, or can define a hollowregion in order to facilitate electrical coupling (e.g., for providing apathway for an electrical connection, for delivering a fluid to theprotrusion to facilitate deflection and/or expansion), as describedfurther below.

The array of channels 130 of the housing 105 b is preferably distributedacross the array of protrusions, and functions to facilitate delivery ofa solution for electrical coupling to the permeable bodies associatedwith the array of protrusions 120. As such, the array of channels 130 ispreferably in fluid communication with the array of permeable bodies110, but can alternatively be configured to deliver the solution to thearray of permeable bodies 110 in any other suitable manner. Each channel131 of the array of channels 130 is preferably defined as a void withina protrusion 121 of the array of protrusions 120, wherein the void hasan opening 132 that provides access into the channel 131 from theexterior of the housing 105; however, one or more channels of the arrayof channels 130 can alternatively be sealed to prevent access from theexterior of the housing 105. The array of channels 130 can be associatedwith the array of protrusions 120 in a one-to-one manner, in amany-to-one manner, or a less-than-one-to-one manner. In one example, asshown in FIGS. 7A and 7B, the array of channels 130′ is defined as a setof voids that longitudinally pass through the array of protrusions 120in a one-to-one manner, wherein each channel is open to the exterior ofthe housing 105 b along a longitudinal surface of a correspondingprotrusion 121′ configured to interface with the scalp of the user. Inanother example, as shown in FIGS. 8A and 8B, the array of channels 130″is defined as a set of voids that longitudinally pass through the arrayof protrusions 120″ in a one-to-one manner, wherein each channel is opento the exterior of the housing at a distal portion of a correspondingprotrusion 121″ configured to interface with the scalp of the user. Thearray of channels 130 can, however, be defined relative to the array ofprotrusions 120 in any other suitable manner.

A lumen of a channel 131 of the array of channels 130 can have anysuitable cross-section. For instance, in variations, cross-sections atone or more regions of a channel 131 can be polygonal or ellipsoidal,and in a specific example, a non-circular cross section can preventrotation of a permeable body 111 situated within a channel 131.

Preferably, each channel 131 in the array of channels 130 is configuredto at least partially surround one or more permeable bodies of the arrayof permeable bodies 110, such that the permeable body(ies) are at leastpartially contained within an interior portion of the array of channels130. In a first variation, an opening along a longitudinal surface of aprotrusion 121 extending laterally from the housing 105 b can beconfigured to receive one or more permeable bodies of the array ofpermeable bodies 110 into an associated channel 131, as shown in FIG.7A. In a second variation, an opening at a distal portion of aprotrusion 121 extending perpendicularly from a broad surface of thehousing 105 b can be configured to receive one or more permeable bodiesof the array of permeable bodies 110 into an associated channel 131, asshown in FIGS. 8A and 8B. In surrounding the permeable bodies, the arrayof channels 130 preferably exposes portions of the permeable bodies(e.g., in wet and dry states) such that at least a portion of apermeable body 111 extends beyond a channel 131; however, the array ofchannels 130 can alternatively substantially surround the permeablebodies, at least in a dry state, such that delivery of a solution forelectrical coupling to the permeable bodies allows the permeable bodiesto expand beyond boundaries of the array of channels 130.

The array of channels 131 and/or the array of protrusions can, however,be alternatively configured in any other suitable manner. For instance,multiple protrusions 121 of the array of protrusions 120 can beconfigured to grip a single or multiple permeable bodies, such that apermeable body 111 is retained within a space defined external toprotrusions of the array of protrusions 120. Furthermore, in any of theabove variations and examples, one or more protrusions and/or one ormore channels can include features configured to retain a permeable body111 in position. In a first variation, an interior portion of a channel131 can include protruding elements configured to retain a permeablebody 111. In one example, as shown in FIGS. 7A and 7B, an interiorportion of a channel 131 can include a corrugated surface 134 havingridges 133′ that are medially oriented relative to (e.g., within) anopening 132 of the channel 131, wherein the ridges 133′ facilitateretention of a permeable body 111 within the channel 131 and the spacesbetween ridges 133′ facilitate passage of solution from the channel 131to more completely wet the permeable body 111. In providing mediallyoriented ridges 133′, the ridges 133′ can thus define protrudingelements that extend from a surface (i.e., an inner surface) of anopening 132 and protrude into the opening 132 to provide permeable bodyretention and/or solution passage functions. In another example, asshown in FIG. 7C, an interior portion of a channel 131 can includespiked ridges 133″ that are medially oriented relative to an opening135″ of the channel 131, wherein the spiked ridges 133″ facilitateretention of a permeable body 111 within the channel 131. In variationsof this example, the spiked ridges 133″ can be angled away from theopening (e.g., into the housing, in a distal-to-proximal direction) toprovide a mechanism that prevents extraction of the permeable body infrom the channel 131, or can alternatively be oriented at any othersuitable angle. In a second variation, an exterior surface can includeprotruding elements 133 configured to retain a permeable body 111. Inexamples similar to those described above, an exterior surface of aprotrusion 121 can include a corrugated surface 134 of ridges 133′and/or spiked ridges 133 that facilitate retention of a permeable bodywithin a spaced defined between protrusions.

In any of the above variations and examples of the array of channels130, protruding elements can be located throughout the depth of thechannel 133, or can be isolated to regions of a channel. For instance,in some variations, the protruding elements can be isolated to distalportions of a channel 131 (e.g., portions configured close to the user'sbody upon application of the system 100 to the user), and substantiallyvoid from proximal portions of the channel 131.

Furthermore, some variations of the system 100 can entirely omitpermeable bodies, and utilize appropriately sized openings 132 of thearray of channels 130 to control delivery of a solution that facilitateselectrical coupling between the system 100 and the body region of theuser. For instance, in one variation, as shown in FIG. 9A, a lumen of achannel can terminate in an opening 132 configured at a distal portionof the channel 131/protrusion 121 (e.g., proximal the user's scalp uponcoupling of the system 100 to the user), wherein the opening 132 issized such that an absence of forcing pressure maintains solution withinthe channel 131 without uncontrollable leaking of solution from theopening 132. To this end, the channel 131 can be formed of a wettable orhydrophilic substance or treated on its interior surface with a wettableor hydrophilic agent to further retention of the solution within thechannel 131. Alternatively, a permeable body or membrane can be includedentirely within the channel 131 (i.e. with minimal or no contact betweenthe permeable body or membrane and the user), in order to minimize orlimit solution flow in the absence of forcing pressure. In thesevariations, provision of a forcing pressure would then allow acontrolled amount of solution for electrical coupling to be exuded fromthe opening 132 to facilitate electrical coupling between the system 100and the user, without a porous body as an intermediary. In one specificexample of this variation, as shown in FIG. 8C, each of an array ofprotrusions 120 extending perpendicularly from a broad surface of thehousing 105 b can include a channel that terminates in an opening 132 ata distal end of the protrusion 121, wherein the opening has a dimensionfrom 0.5-0.8 mm in diameter (e.g., to accommodate saline). In anotherspecific example of this variation, each of an array of protrusions 120extending laterally from the housing 105 b can include a channel thatterminates in a set of openings configured along a length of a surfaceof the protrusion 121 configured to interface with the body region ofthe user, wherein the opening(s) each have a dimension from 0.5-0.8 mmin diameter (e.g., to accommodate saline). In variations of the aboveexamples, the opening(s) 132 can alternatively comprise any othersuitable dimensions. For instance, larger dimensions for the opening(s)132 can be configured to accommodate a solution for electrical couplingthat is more viscous than saline. In other variations of the system 100,the permeable bodies can be replaced by permeable or semi-permeablemembranes (e.g., a thin film composite membrane, a permeable textile),located at the distal portion of at least one channel 131 of the arrayof channels 130, in order to make wetted contact with the user's scalpwhile minimizing bulk fluid flow in the absence of forcing pressure.

In still another variation, an example of which is shown in FIG. 9B, apermeable substrate material of a housing 105 b can be processed (e.g.,treated with radiation to form a mask) to define open regions 107configured to absorb and deliver a solution of electrical coupling fluidtoward a body region of the user, and closed regions 108 configured toblock transmission of the solution of electrical coupling fluid. In onesuch example, the open regions 107 can comprise an open cell foam andthe closed regions 108 can comprise a closed-cell or impermeable foam,or open-cell foam made substantially impermeable by treatment with asurface treatment such as heat or a chemical sealant, configured tosubstantially block transmission of a solution of electrical couplingfluid.

The manifold 140 is fluidly coupled to the array of channels 130, andfunctions to distribute the solution to the array of channels 130.Preferably, the manifold 140 is defined within a cavity of the housing105 b that is in fluid communication with the array of channels 130;however, the manifold 140 can alternatively be defined external to thehousing 105, while being in fluid communication with the array ofchannels 130 through the housing. As shown in FIGS. 1, 7C, 10A, and 10B,the manifold preferably includes a set of conducting pathways 141 influid communication with the array of channels 130, and a reservoir 145coupled to the set of conducting pathways 141, wherein the reservoir isconfigured to retain a volume of a solution for delivery into the set ofconducting pathways 141 and to the array of channels 130.

The set of conducting pathways 141 functions to convey a solution ofelectrical coupling fluid to the array of permeable bodies 110 (oralternatively, to openings 132 of the array of channels), such that thebody region of the user can be coupled to the electronics subsystem 150upon application of the system 100 to the user. As such, the set ofconducting pathways 141 preferably comprises at least one pathwaythrough the array of protrusions 120. In some variations, the set ofconducting pathways 141 can travel from the reservoir 145 to fluidlycouple to the array of channels 130, wherein at least one of the set ofconducting pathways 141 and the reservoir 145 is in electricalcommunication with the electronics subsystem 150 by way of one or moreelectrical coupling regions, as described in further detail below. Inthese variations, the set of conducting pathways 141 can be definedthrough a single cavity within the housing 105 b and/or within cavitiesof the array of protrusions 110. Furthermore, in these variations, theset of conducting pathways 141 can be associated with the array ofchannels 130 in a one-to-one manner, in a many-to-one manner, or in aless-than-one-to-one manner. In some variations, wherein the set ofconducting pathways 141 extend from a single reservoir 145, as describedin further detail below, conducting pathways positioned further from acentral portion of the reservoir 145 can be configured to provide alower amount of fluid resistance, as compared to conducting pathwayspositioned closer to the central portion of the reservoir 145, in orderto facilitate substantially uniform delivery of a solution within thereservoir 145 to the set of conducting pathways 141. In examples, asshown in FIGS. 10A and 10B, conducting pathways positioned further froma central portion of the reservoir 145 can be configured to have agreater cross-sectional dimension (e.g., width, height), as compared toconducting pathways positioned closer to the central portion of thereservoir 145, and/or conducting pathways positioned further from acentral portion of the reservoir 145 can be configured to have a greaterexposed volume (e.g., greater length, greater width, greater depth)within the reservoir 145, as compared to conducting pathways positionedcloser to the central portion of the reservoir 145.

In a specific example, as shown in FIG. 11A, the set of conductingpathways 141′ can be configured adjacent to and run parallel to thearray of channels 130, wherein each conducting pathway of the set ofconducting pathways 141′ is paired with a channel 131 in a one-to-onemanner. In this specific example, the set of conducting pathways 141′ isconfigured to extend through protrusions that extend laterally from thehousing 105, and the set of conducting pathways 141′ is configuredimmediately proximal to (e.g., side-by-side with) the array of channels130 in order to facilitate delivery of the solution to the array ofchannels 130. In another specific example, as shown in FIG. 11B, the setof conducting pathways 141″ can be configured to run in series with thearray of channels 130 in a one-to-one manner. In this specific example,the set of conducting pathways 141″ is configured to extend throughprotrusions that extend perpendicularly from a broad surface of thehousing 105, and the set of conducting pathways 141″ is configuredimmediately proximal to (e.g., end-to-end with) the array of channels130 in order to facilitate delivery of the solution to the array ofchannels 130. However, in other variations and examples, the set ofconducting pathways 141 can alternatively be configured relative to thearray of channels 130 in any other suitable manner.

As shown in FIGS. 1B, 7C and 11A, in some variations, one or morechannels 131 of the housing 105 b can comprise or be coupled to abarrier 142 configured to prevent passage of a permeable body 111 pastthe 142 in a distal-to-proximal direction. As such, in these variations,a permeable body 111 can be retained in position by the barrier 142 thatprevents passage of the permeable body from a channel 131 into one ofthe set of conducting pathways 141. In examples, the barrier 142 cancomprise any one or more of: an extension that protrudes into aninterior portion of a channel 131 and/or one of the set of conductingpathways 141 and allows fluid transmission between the channel and theconducting pathway, a membrane spanning a cross-section of a channel 131and/or one of the set of conducting pathways 141 that allows fluidtransmission across the membrane but blocks passage of the permeablebody, and any other suitable barrier that allows fluid transmission butprevents passage of a permeable body 111 into one of the set ofconducting pathways 141. Variations of the housing 105 b can, however,entirely omit barriers 142 between the set of channels 130 and the setof conducting pathways 141.

In alternative variations, one or more of the set of conducting pathways141 can be configured to travel along an exterior portion of one or moreof the array of protrusions 120. In still other variations, the set ofconducting pathways 141 can be configured to travel along a portion ofan exterior of the array of protrusions 120, and to pass into aprotrusion of the array of protrusions 120, in order to facilitateelectrical coupling of the array of porous bodies 110 to the electronicssubsystem 150. The electrical coupling to the electronics subsystem 130can, however, be provided in any other suitable manner.

The reservoir 145 of the manifold 140 is fluidly coupled to the set ofconducting pathways 141, as shown in FIGS. 1B, 10A, and 10B, andfunctions to actively facilitate delivery of a solution of electricalcoupling fluid into the set of conducting pathways 141 (e.g., towardpermeable bodies of the array of permeable bodies). The reservoir 145can be an on-board reservoir integrated with housing 105, or canalternatively be an off-board reservoir temporarily or permanentlycoupled to the housing 105 b to facilitate delivery of the solution ofelectrical coupling fluid into the set of conducting pathways 141. Thereservoir 145 can be a refillable reservoir or a single-use reservoir,and in some variations, can be configured to receive a container offluid (e.g., a sealed fluid packet) that can be penetrated or broken inorder to facilitate fluid delivery. In a single-use variation, thereservoir 145 can be configured with a burstable membrane that can bepenetrated or broken, e.g. by forcing pressure or a plunger acting toprovide forcing pressure, in order to facilitate fluid delivery in theactivated state while preventing fluid delivery prior to activation. Inone variation, as shown in FIGS. 10A and 10B, the reservoir 145 can be arecess at a superior portion of the housing 105 b (i.e., in theorientation shown in FIG. 10A) configured to receive the solution,wherein the recess is fluidly coupled to the set of conducting pathways141. In an example of this variation, the reservoir 145 can include acap 146 that seals fluid within the reservoir 145, wherein the cap 146allows the reservoir 145 to be accessed in order to enable replenishingof the solution. In this example, the cap 146 can provide a hermeticseal for the reservoir 145 and can additionally or alternatively enableventing of the reservoir for metering of fluid delivery. Furthermore,the cap 146 can include a port 147 configured to facilitate delivery ofthe solution into the reservoir 145/manifold 140, and in some instances,to facilitate driving of the solution from the reservoir into the set ofconducting pathways 141. Alternatively, the reservoir 145 can omit a capand be prepackaged with or configured to receive the solution in anyother suitable manner.

In some variations, the system 100 can additionally or alternativelycomprise a fluid delivery system 148, as shown in FIG. 1B, configured toactively deliver fluid into the set of conducting pathways 141 of themanifold 140, for example by producing positive pressure flow, negativepressure flow, or any combination of positive and negative pressure flow(e.g., in bidirectional flow). The fluid delivery system 148 cancomprise an actuator (e.g., motor, solenoid, plunger system, diaphragm,external compressor, etc.), pump, or any other suitable element thatfacilitates fluid flow. Alternatively, a solution of electrical couplingfluid can be delivered from the reservoir 145 passively, for example, bygravity, or can alternatively be delivered into permeable bodies of thearray of permeable bodies 110 by absorbing a fluid present in theenvironment. The amount of fluid delivered is preferably configured toreduce hair-wetting of the user; however, any other suitable amount offluid can be delivered into the set of conducting pathways 141 tofacilitate electrical coupling between the system 100 and the user.

In one example of the manifold 140 of the housing 105 b comprising areservoir 145 and a fluid delivery system 148, as shown in FIGS. 1B and9A, the reservoir 145 and the fluid delivery system 148 are configuredto provide a pressure that forces the solution of electrical couplingsolution into the set of conducting pathways toward openings 132 of thearray of channels 130, thus enabling electrical coupling between theuser and the system 100, while minimizing hair-wetting. In one variationof this example omitting permeable bodies and including a solution ofviscous electrical coupling fluid (e.g., electrode gel), the solutioncan have sufficient surface tension, such that the solution does notexit from the openings 132 unless pressure is increased within thereservoir 145. Upon placement of the housing 105 b with the openings 132facing the user's scalp, an increase in pressure within the reservoir145, provided by the fluid delivery system 148, forces the solution ofviscous electrical coupling fluid out of the openings 132 in a mannerthat provides electrical contact (e.g., a contiguous connection) withthe user's scalp while minimizing an amount of exuded material from theopenings 132. Then, when the system 100 is desired to be uncoupled fromthe user, the fluid delivery system 148 of this example can beconfigured to decrease pressure within the reservoir 145 (e.g., to apressure level equal to or less than a pressure level provided beforeplacement at the user's scalp). The pressure decrease allows thesolution of viscous electrical coupling fluid to be retracted, throughthe openings 132, and back into the reservoir 145 until a subsequentperiod of usage. In this example, exuding the solution of viscouselectrical coupling fluid during use and retracting the solution betweenusages can further function to preserve the solution and extend itslifetime of usability as well as minimize the amount of solution left onthe user's scalp and hair. Additionally, in another example, thedecrease in pressure and corresponding retraction of electrical couplingfluid can be omitted. In another variation omitting permeable bodies andincluding a solution of electrical coupling fluid, an increase inpressure within the reservoir 145 can force the solution out of theopenings 132 in a manner that provides electrical contact, but once thisoccurs, contact can be maintained by a combination of mechanicalcompliance of the array of protrusions 120, surface tension, and wettingbetween the solution and the openings 132 as well as the user's scalp,rather than by high viscosity of the electrical coupling fluid. Themanifold 140 of the housing 105, including the reservoir 145, the set ofconducting pathways 141, and/or the fluid delivery system 148 can,however, be configured in any other suitable alternative manner. Forinstance, subsets of the array of protrusions 120, the array of channels130, and the set of conducting pathways 141, as defined by the housing105, can form independent (e.g., isolated) conducting units, such thateach unit can be configured individually (e.g., one unit can serve as acathode, and another unit can serve as an anode). Additionally oralternatively, a single housing 105 b can comprise multiple sets ofmanifold-reservoir-conducting pathway assemblies, wherein each assemblyis held at a different potential, and wherein one or more subsets of thearray of channels 130 and/or openings 132 of the array of channels 130can be configured to couple to assemblies at different potentials.

While two embodiments are described above, variations of the system 100can include any suitable combination of one or more portions of thefirst embodiment and the second embodiment described above with eachother, or with any other suitable electrode system 100. A few suchexamples of the electrode contact assembly are described in Section1.1.4 below.

1.1.4 System—Electrode Contact Assembly Examples

In a first example, the array of protrusions 120 of a housing 105comprises a linear array of teeth extending laterally from the housing105, each protrusion 121/tooth defining a wedge-shaped leading edgeconfigured to deflect hair in order to facilitate coupling. In thisexample, each tooth comprises a length longer than the thickness of theuser's hair, in order to facilitate electrical coupling with the scalpof the user. In this example, a distal portion of each protrusion121/tooth includes an opening 132 in fluid communication with one of anarray of conducting pathways 141 and configured to surround a permeablebody 111 of an array of porous bodies 110, wherein the permeable body111 is configured to transmit a solution of electrical coupling fluidthat contacts the user's skin. Furthermore, in this example, the distalportion of each protrusion 121/tooth comprises a concave surfaceconfigured to complement a convex surface of the user's scalp. In theexample, the permeable body 111 is seated within a channel 131 of itsprotrusion 121/tooth in a dry and compressed state, such that it extendsminimally or does not extend beyond the concave surface of the tooth inthe dry state; however, upon absorption of the solution of electricalcoupling fluid, the permeable body 111 expands both parallel andperpendicular to the user's skin surface, in order to provide anincreased contact surface area, displace hair, and decrease anelectrical resistance of the electrode-to-skin interface. Placement ofhousing 105, in this example, comprises passing a leading edge of thearray of protrusions 120 through the user's hair to make contact withthe skin, wherein initial contact is made posterior to a desired finalelectrode location. Placement further comprises movement of the array ofprotrusions 120 parallel to a skin surface of the user, while followinga path of the leading edge of the array of protrusions 120, such thathair is deflected about the wedged-shaped leading edge and contact ismade with the user's skin at a desired final location. Upon reading thedesired final location, a reservoir 145 coupled to a set of conductingpathways 141 in fluid communication with the array of permeable bodies110 is configured to deliver the solution to the array of permeablebodies 110, thus enabling fluid absorption and electrical coupling withthe skin of the user.

In a second example, the array of protrusions 120″ of a housing 105comprises a two-dimensional array of conical protrusions or “spikes”extending perpendicularly from a broad surface of the housing 105, eachspike in the array tapering to a blunted end configured to facilitatecoupling without penetrating the skin of a user. In this example, eachprotrusion 121/spike comprises a length longer than the thickness of theuser's hair in order to facilitate electrical coupling with the user,and furthermore, distal portions of the array of protrusions 120 definesa non-continuous concave surface configured to conform to a convexsurface of the user's skull. In this example, a distal portion of eachprotrusion 121/spike includes an opening 132 of a channel 130 configuredto partially surround a porous body 111 that contacts the user's skinafter hair deflection has occurred. Furthermore, in this example, thedistal portion of each protrusion 121/spike also comprises a concavesurface configured to complement a convex surface of the user's skull.Furthermore, in the example, the permeable body 111 is seated within achannel 131 of a protrusion 121/spike in a dry and compressed state,such that it does not extend beyond the channel 131 of the spike in thedry state; however, upon fluid absorption, the permeable body 111expands both parallel and perpendicular to the user's skin surface, inorder to increase a contact surface area provided by the permeable body111, displace hair, and decrease an electrical resistance of theelectrode-to-skin interface. Placement of the housing 105, in thisexample, comprises placement of the array of protrusions 120/spikes ontoa target surface of the user's body, applying pressure to the array ofprotrusions 120 in a direction perpendicular to the surface of theuser's body, and laterally moving the array of protrusions 120 (e.g., incircular or side-to-side motions) while applying pressure, thusdisplacing hair, until contact between the array of permeable bodies 110and the user's skin occurs. In this example, placement occurs by aratchet-like mechanism, due to the tendency of hair to behave in aspring-like manner near hair follicle-skin junctions. Upon placement atthe target location, a reservoir 145 coupled to a set of conductingpathways 141 in fluid communication with the array of permeable bodies110 is configured to deliver the solution to the array of permeablebodies 110, thus enabling fluid absorption and electrical coupling withthe skin of the user.

In a third example, as shown in FIGS. 8B-8C, the array of protrusions120 of a housing 105 b comprises a two-dimensional array of conicalprotrusions extending perpendicularly from a broad surface of thehousing 105, each spike in the array tapering to a blunted endconfigured to facilitate coupling without penetrating the skin of auser. In this example, each protrusion 121 comprises a length longerthan the thickness of the user's hair in order to facilitate electricalcoupling with the user, and the array of protrusions 120 defines acircular footprint having a diameter of approximately 5 cm. In thisexample, the array of protrusions 120 is arranged in a series ofconcentric circles, with a central protrusion 122 and a first ring 123of six protrusions (or between four and six protrusions) surrounding thecentral protrusion 122. Variations of the third example can, however,include any suitable number of concentric rings of protrusions, as shownin FIG. 6C. In one variation of the third example, each protrusion 121can surround a channel 131 of an array of channels 130 configured toreceive a permeable body, wherein the channel 131 is configured inseries with a conducting pathway 141 of a manifold 140 configured todistribute a solution of coupling fluid to the channel 131. The channelcan be configured to receive one or more seated permeable bodies in,wherein the permeable bodies do not extend beyond distal portions of thechannels 131 in a dry and compressed state; however, upon fluidabsorption, the permeable bodies 111 can expand both parallel andperpendicular to the user's skin surface, in order to increase a contactsurface area provided by a permeable body 111, displace hair, anddecrease an electrical resistance of the electrode-to-skin interface.Alternatively, the channels may not be configured to receive permeablebodies, and instead terminate in openings at distal ends of the array ofprotrusions that enable fluid to be exuded in a controlled manner.Placement of the housing 105, in this example, comprises placement ofthe array of protrusions 120 onto a target surface of the user's body,applying pressure to the array of protrusions 120 in a directionperpendicular to the surface of the user's body, and laterally movingthe array of protrusions 120 (e.g., in circular or side-to-side motions)while applying pressure, thus displacing hair, until contact between thearray of permeable bodies 110 and the user's skin occurs. In thisexample, placement occurs by a ratchet-like mechanism, due to thetendency of hair to behave in a spring-like manner near hairfollicle-skin junctions. Upon placement at the target location, areservoir 145 coupled to a set of conducting pathways 141 in fluidcommunication with the array of permeable bodies 110 is configured todeliver the solution to the array of permeable bodies 110, thus enablingfluid absorption and electrical coupling with the skin of the user.

In variations of the third example, the housing 105 can include multiplesets of manifold-reservoir-conducting pathway assemblies, wherein eachassembly is held at a different potential, and wherein one or moresubsets of the array of channels 130 and/or openings 132 of the array ofchannels 130 can be configured to couple to assemblies at differentpotentials. In one such variation, as shown in FIG. 12A, a protrusion121 a can include a channel 131 a that has an opening 138 a at aproximal end 128 a, wherein transitioning the opening 138 a betweenproximal and distal positions (e.g., relative to the scalp of the user)enables the channel 131 a to access volumes of solutions of electricalcoupling fluid that are held at different potentials (e.g., a firstpotential 201, a neutral potential 202, and a second potential 203). Ina similar variation, the protrusion 121 a includes a non-fluidconductor, such as a metallic electrical conductor, one part of which isin electrical contact with the solution and another part of which can betransitioned (e.g. with an electromechanical switch) between electricalconnectivity with metallic electrical conductors that are held atdifferent potentials (e.g. a first potential 201, a neutral potential202, and a second potential 203). In another such variation, as shown inFIG. 12B, a protrusion 121 b can include a channel 131 b that has anopening 138 b along a length of the protrusion 121 b, wherein rotatingthe opening 138 b enables the channel 131 b to access volumes ofsolutions of electrical coupling fluid that are held at differentpotentials (e.g., a first potential 201, a neutral potential 202, and asecond potential 203). Variations of the third example can, however, beconfigured in any other suitable manner.

1.1.5 System—Sham Electrode Embodiment

In a first embodiment, the system 100 comprises electrode contactassemblies 101, 102 that function as either a cathode or an anode, inorder to provide a level of electrical stimulation adequate fortreatment (e.g., a non-control treatment). The cathode and the anode ofthe first embodiment of the system 100 are thus preferably separated bya distance that provides an adequate current to achieve the level ofelectrical stimulation needed for treatment. In an example applicationof the first embodiment, the separation between the cathode and theanode causes a current transmitted between them to penetrate the scalpand the brain, thus achieving a treatment level of electricalstimulation. The first embodiment thus comprises a “normal” electrodethat is able to facilitate transmission of an electrical stimulationtreatment (e.g., non-control treatment, or treatment intended to affectphysiological function) to a user.

In a second embodiment, the electrode system 100 can include anelectrode contact assembly that includes both a cathode and an anode, inorder to provide a level of electrical stimulation adequate for acontrol treatment. In comparison to the first embodiment, the cathodeand the anode of the second embodiment are separated by a smallerdistance, thus providing a smaller current that achieves a lower levelof electrical stimulation. In an example of the second embodiment, theclose proximity of the cathode and the anode causes a currenttransmitted between them to pass primarily through the scalp (and notinto or through the brain), thus achieving a control level of electricalstimulation. The second embodiment thus comprises a “sham” electrodethat is able to facilitate transmission of a control level of electricalstimulation (e.g., control treatment, non-therapeutic treatment, ortreatment not substantially affecting physiological function) to a user.

The second embodiment can function to replicate a duration of sensation(e.g., itching/tingling sensation) comparable to that provided by afirst embodiment electrode system 100 without providing non-controltreatment-level stimulation; thus, the second embodiment of the system100 can provide a suitable control treatment for applications in whichan electrical stimulation treatment requires an appropriate controltreatment. In examples similar to those of the examples described inSection 1.1.1, “sham” electrodes are preferably configured to appearidentical to “normal” electrodes (e.g., both the “sham” and the “normal”electrodes can comprise an array of teeth and/or an array of spikes), inorder to facilitate conduct of clinical studies with appropriateblinding and control treatments.

1.2 System—Electronics and Coupling Subsystems

As shown in FIGS. 1A and 1B, the system 100 can further comprise anelectronics subsystem 150 comprising a power module 151 and a stimulusgenerator 153. The electronics subsystem 150 functions to transmitstimulation and facilitate bioelectrical signal detection in cooperationwith elements of the housing 105 and the array of permeable bodies 110.In some embodiments, the electronics subsystem 150 can additionally oralternatively include a signal processing module 155 configured tocondition and/or to preprocess biosignals received from the user tofacilitate further analyses. The electronics subsystem 150 can comprisea printed circuit board (PCB) configured to provide a substrate and tofacilitate connections between electronic components, but canalternatively comprise any other suitable element(s). The electronicssubsystem 150 is preferably configured to couple to the user by way of acoupling subsystem 160 described in further detail below, and can beintegrated with a housing 105 or entirely distinct from the housing 105.

The power module 151 of the electronics subsystem 150 functions to serveas an electrical power source for the system 100, in order to provideregulated power to the system 100. The power module 151 can comprise abattery, but can alternatively comprise any other suitable electricalpower source. In variations wherein the power module 151 comprises abattery, the battery is preferably a lithium-ion battery that isconfigured to be rechargeable, but can alternatively be any otherappropriate rechargeable battery (e.g., nickel-cadmium, nickel metalhydride, or lithium-ion polymer). Alternatively, the battery may not bea rechargeable battery. The battery is also preferably configured tohave any appropriate profile such that the battery provides adequatepower characteristics (e.g., cycle life, charging time, discharge time,etc.) for stimulation and/or sensing using the electrode system 100.

In embodiments wherein the power module 151 comprises a battery, andwherein the battery is rechargeable, the electronics subsystem 130 canalso comprise a charging coil that functions to facilitate inductivecharging of the battery. The charging coil can be coupled to the batteryand configured to convert energy from an electromagnetic field (e.g.,provided by a charging dock), into electrical energy to charge thebattery. Inductive charging provided by the charging coil thusfacilitates user mobility while interacting with the system 100. Inalternative variations, however, the charging coil can altogether beomitted (e.g., in embodiments without a rechargeable battery), orreplaced by a connection configured to provide wired charging of arechargeable battery.

The stimulus generator 153 of the electronics subsystem 150 ispreferably electrically coupled to the power module 151 and a controlmodule 154, and functions to transmit an electrical stimulationtreatment, through the electrode contact assemblies 101, 102, andprovide adjustability in the parameters of the electrical stimulationtreatment. The stimulus generator 153 preferably comprises a currentgenerator, but can additionally or alternatively include a voltagegenerator and/or any other suitable generator configured to facilitatetransmission of an electrical stimulation treatment. The stimulusgenerator 153 is preferably configured to facilitate transmission oftranscranial electrical stimulation (TES) in the form of at least oneof: transcranial direct current stimulation (tDCS), transcranialalternating current stimulation (tACS), transcranial magneticstimulation (TMS), transcranial random noise stimulation (tRNS, e.g.,band-limited random noise stimulation), and transcranial variablefrequency stimulation (tVFS). Additionally or alternatively, thestimulus generator 153 can be configured to provide stimulation in apulsatile manner. As such, the stimulus generator 153 can provide anyone or more of: a direct current (DC), an alternating current (AC), anAC component superimposed on a DC component, a monophasic pulsatilewaveform, a symmetrical biphasic pulsatile waveform, an asymmetricalbiphasic pulsatile waveform, and any other suitable stimulation profile.The waveform produced by the current generator 153 preferably can bedescribed by parameters comprising amplitude and duration, butadditionally or alternatively comprising any other suitableparameter(s), such as modulation frequency, step size, mean amplitude,or RMS value. Furthermore, any one or more of the above parameters canbe configured to be modulated by the stimulus generator 153, such thatthe stimulus generator 153 can produce any one or more of: modulatedamplitudes, modulated frequencies, and modulated pulse durations (e.g.,modulated parameters characterized by exponential decay, exponentialgrowth, or any other suitable growth or decay profiles). In coupling toa control module 154, the control module 154 is preferably configured toreceive a treatment command and to provide an output to the stimulusgenerator 153 that adjusts one or more parameters of the electricalstimulation treatment as facilitated by the stimulus generator 153 andan electrode contact assembly 101, 102. The outputs from the controlmodule 154 can be delivered to the stimulus generator 153 continuously,intermittently, in real time, in non-real time, and/or in any othersuitable manner. While one stimulus generator 153 is described, theelectronics subsystem 150 can, in some variations, comprise more thanone stimulus generator 153, where the electronics subsystem 150 isconfigured to multiplex output of the additional stimulus generators toone or more electrode contact assemblies 101 and 102 or subsectionsthereof.

The signal processing module 155 of the electronics subsystem 150functions to preprocess biosignals received from the user to facilitatefurther analyses of received biosignals. Preferably, the signalprocessing module 155 is configured to amplify biosignals from the user;however, the signal processing module can additionally or alternativelybe configured to perform any one or more of: filtering of biosignalsfrom the user, conversion of analog signals from the user into digitalsignals (e.g., by an analog-to-digital converter), and preprocessing ofbiosignals in any other suitable manner. As such, the signal processingmodule 155 can comprise an amplifier configured to amplify signalsand/or shift signals relative to a reference voltage, wherein theamplified signals can be amplified before and/or after multiplexing. Thesignal processing module 155 can also comprise a filter configured tofilter noise, interfering signals, and/or transients, wherein the filtercan comprise a low pass filter, a high pass filter, and/or a band passfilter.

The electronics subsystem 150 can comprise any other suitable element,such as a data link 157, which functions to transmit an output of atleast one element of the system 100 to a mobile device 158 or othercomputing device. Preferably, the data link 157 is a wireless interface;however, the data link can alternatively be a wired connection. In afirst variation, the data link 157 can include a Bluetooth module thatinterfaces with a second Bluetooth module included in a mobile device orexternal element, wherein data or signals are transmitted over Bluetoothcommunications. The data link 157 of the first variation canalternatively implement other types of wireless communications, such as3G, 4G, radio, or Wi-Fi communication. In the first variation, dataand/or signals are preferably encrypted before being transmitted by thedata link. For example, cryptographic protocols such as Diffie-Hellmankey exchange, Wireless Transport Layer Security (WTLS), or any othersuitable type of protocol may be used. The data encryption may alsocomply with standards such as the Data Encryption Standard (DES), TripleData Encryption Standard (3-DES), or Advanced Encryption Standard (AES).

The coupling subsystem 160 comprises a first electrical coupling region161 in electrical communication with an interior portion of the housing105 and a second electrical coupling region 162, configured to couplethe first electrical coupling region to the electronics subsystem. Thecoupling subsystem 160 thus functions to allow outputs of theelectronics subsystem 150 (e.g., of the stimulus generator 153) to betransmitted through the solution of electrical coupling fluid (e.g.,saline) in communication with (e.g., saturating, absorbed by, etc.) thearray of permeable bodies 110, in order to enable transmission ofelectrical stimulation to the body region of the user. The couplingsubsystem 160 can additionally or alternatively function to enablereception of signals (e.g., signals from the user, signals indicative ofimpedance from any electrical interface of the system 100, etc.), whichcan facilitate biosignal detection from the user and/or ensure properfunction of the system 100. The first electrical coupling region 161 andthe second electrical coupling region 162 are preferably composed ofconductive metallic elements (e.g., copper, gold, silver, brass,aluminum, etc.), but can additionally or alternatively be composed ofany other suitable element(s). Preferably, the first electrical couplingregion 161 and the second electrical coupling region 162 are configured(e.g., processed, positioned, etc.) in a manner that prevents corrosion;however, the first and the second electrical coupling regions 161, 162can alternatively be configured in any other suitable manner. Forinstance, variations of either the first electrical coupling region 161and the second electrical coupling region 162 may not be processed toprevent corrosion, such that one or more aspects of the system 100 areconfigured for one-time-use.

In interfacing with each other, the first electrical coupling region 161and a second electrical coupling region 162 can mate with each other ina reversible manner, such that an electrode unit can be removably andreversibly coupled to other portions of the system (e.g., portionsincluding the electronics subsystem 160). However, the first electricalcoupling region 161 and a second electrical coupling region 162 canalternatively couple with each other in a not easily reversed manner. Invariations, coupling between the first electrical coupling region 161and a second electrical coupling region 162 can be provided using one ormore of a mechanical coupling mechanism and a magnetic couplingmechanism. In a first specific example, as shown in FIGS. 5A, 5B and 5C,the first electrical coupling region 161 can comprise a tab (i.e., as amale connection) that mechanically mates with a pin within a socket(i.e., as a female connection) of the second electrical coupling region162.

Additionally or alternatively, in a second specific example, as shown inFIG. 5C, the first electrical coupling region 161 and a secondelectrical coupling region 162 can be promoted to couple with each otherby using magnetic/ferromagnetic materials at desired regions of thesystem 100, wherein the magnetic/ferromagnetic materials enable magneticcoupling and consequently promote physical and electrical couplingbetween the first electrical coupling region 161 and the secondelectrical coupling region 162.

The first electrical coupling region 161 preferably has portions atleast partially situated within an interior portion of the housing 105,and functions to enable stimulation transmission from the electronicssubsystem 150 through the array of permeable bodies 110 to the user. Inrelation to the first embodiment of the housing 105 and substrate region50 described in Section 1.1.2 above, the first electrical couplingregion 161 preferably interfaces with a set of conductors 60 thatprovide different subregions of the substrate region 50 with differentcharacteristics (e.g., different polarities). However, the set ofconductors 60 (and/or other aspects of the system 100) can additionallyor alternatively be configured to provide all regions of the substrateregion 50 with substantially the same characteristics (e.g., in terms ofpolarity) In variations, the portion of the first electrical couplingregion 161 that is interior to the housing 105 can include a metallicpad 62 (or other conducting pad) that interfaces with at least a portionof the substrate region 50, and an electronics substrate 64 (e.g.,printed circuit board, flex printed circuit, etc.) that interfaces withthe metallic pad 62. The electronics substrate 64 can further includeone or more connectors 65 that interface with the second electricalcoupling region 162 that is coupled to the electronics subsystem 160, asshown in FIG. 5D.

In variations, the connectors 65 of the electronics substrate 64 caninclude one or more of a detection connector 65 a and a stimulationconnector 65 b. In one example, as shown in FIG. 5D, a detectionconnector 65 a can be coupled, from the electronics substrate 64, to astimulation connector 65 b with a resistor. In the example, one or morestimulation connectors 65 b, as shown in FIG. 5D, can be coupled fromthe electronics substrate 64 to the metallic pad 62 in order to providea conductive path to at least a portion of the array of permeablebodies. Also shown in FIGS. 5A-5D, the electronics substrate cancomprise more than one stimulation connector 65 b that each couple todifferent regions of the metallic pad 62, in providing a conductive pathto corresponding sub-portions of the array of permeable bodies 110.

In more detail, each unit of the electrode system 100 can be providedwith a characteristic resistor value (e.g., 1 MOhm for a central unit101 a of the electrode system, 500 kOhm for a side unit 102 a, 103 a ofthe electrode system, etc.), with detection of the type of electrodeunit associated with the characteristic resistor value, and/or detectionof stimulation-related parameters enabled through a detection circuit ofthe electronics subsystem 160. In one such example detection circuit,the detection circuit 59 can be configured to provide a probe voltage tothe stimulation connector(s) 65 b with respect to a ground, (e.g., avoltage created by a voltage-controlled current source circuit), whilenot providing a complete return path for current to flow through theuser. The probe voltage thus causes a characteristic voltage to occur atthe detection connector 65 a, which depends upon the value of theresistor and the value of the probe voltage. This characteristic voltagecan thus be sensed by the detection circuit 59, which can be used totrigger an alert state (e.g., to output an alert output in relation toappropriateness of the electrode units being used for a desiredstimulation program, in relation to proper electrical behavior of anelectrode unit, in relation to a scenario wherein no electrode unit isinstalled prior to a desired period of use of the system, in relation toa scenario where a foreign body is installed, etc.). However, the firstelectrical coupling region 161 can alternatively be configured in anyother suitable manner.

In one example, the set of conductors 60 of the first electricalcoupling region 161 can provide a first subregion 53 a of the substrateregion 50 with a first polarity, and both a second subregion 53 b and athird subregion 53 c of the substrate region 50 with a second polarity(e.g., with one subregion acting as an anode and with another subregionacting as a cathode, for delivering of band-limited random noisestimulation, etc.). However, the set of conductors 60 can alternativelybe configured relative to the substrate region 50 in any other suitablemanner.

In relation to the second embodiment of the housing 105 described inSection 1.1.3 above, the first electrical coupling region 161 can beconfigured proximal at least one of an interior surface of the manifold140, the set of conducting pathways 141, and the array of channels 130.The first electrical coupling region 161 is preferably configured tomaintain contact with the solution of electrical coupling fluid whilestimulation is being provided to the user and/or while signals are beingdetected, and as such, is preferably configured along a path of fluidflow of the solution throughout the housing. In one variation, the firstelectrical coupling region 161 is positioned near a distal portion of aninterior of the housing 105 (e.g., at a distal portion within themanifold 140), upon coupling of the housing 105 to the user, such thatgravitational force facilitates maintenance of contact between the firstelectrical coupling region 161 and the solution of electrical couplingfluid. Additionally, in this variation the electrical coupling regioncan be configured to extend from the distal portion of the interior ofthe housing 105, and to exit from the housing 105, in order to couple tothe electronics subsystem 150 (i.e., by way of the second electricalcoupling region). The first electrical coupling region 161 can, however,be configured in any other suitable manner. For instance, the firstelectrical coupling region 161 can include one or more leads that extendinto the set of conducting pathways 141/array of channels 130 to enablestimulation transmission to the user and/or signal detection from theuser.

The second electrical coupling region 162 is preferably positionedexterior to the housing 105, and configured to couple to the firstelectrical coupling region 162 to enable stimulation transmission to theuser and/or signal detection from the user. The second electricalcoupling region 162 and the first electrical coupling region 161 arepreferably composed of identical materials in order to prevent galvaniccorrosion; however, the second electrical coupling region 162 and thefirst electrical coupling region 161 can alternatively be composed ofnon-identical materials. Preferably, the second electrical coupling 162and the first electrical coupling 161 are configured to be reversiblycoupled to each other, such that a portion of the first electricalcoupling 161 and the second electrical coupling 162 mate with eachother. As such, in examples, the first and the second electricalcouplings 161, 162 can form a male-female coupling 163 that is isolatedfrom the solution of electrical coupling fluid in order to providemodularity in the system 100. As such, any corrosion or passivation ofthe first electrical coupling region 161, within the housing 105, can beisolated from the second electrical coupling region 162 (e.g., in avariation in which the elements of the housing 105 are not configured tobe reusable). Alternatively the first electrical coupling region 161 andthe second electrical coupling region 162 can be of unitaryconstruction, such that the first electrical coupling region 161 and thesecond electrical coupling region 162 have a single joined configurationand cannot be uncoupled from one another. In an additional variation,the coupling subsystem 160 projects distally to the array of permeableelements 110 (e.g., through channels of the array of channels 130),allowing outputs of the electronics subsystem 150 (e.g., of the stimulusgenerator 153) to be transmitted to the array of permeable bodies 110without the need for a manifold 140 or a continuous path of electricalcoupling fluid from the interior portion of the housing 105 to eachpermeable body 111.

1.3 System—Other Elements

The system 100 can additionally further comprise a positioning module170, as shown in FIG. 13, which is configured to facilitate placement ofthe electrode system 100 at the user's scalp. The positioning module 170preferably couples to an element of the system 100 (e.g., a housing) ina reversible manner and/or a reconfigurable manner, but canalternatively couple to the element of the system 100 in a permanent ora semi-permanent manner. Additionally, the positioning module 170 can beconfigured to house at least a portion of the electronics subsystem 150,and to provide an electromechanical connection between the electronicssubsystem 150 and an electrode contact assembly 101 b, 102 b by way ofthe positioning module 170. The positioning module 170 can additionallyor alternatively be configured to guide motion of the array ofprotrusions 120 of a housing 105 of the system 100, in order tofacilitate formation of an electrical connection between the user andthe system 100. In one variation, as shown in FIG. 13, the positioningmodule 170 is configured to follow the contour of the user's skull(e.g., as in a helmet, cap, headband, halo, or headset), and includes atleast one track 171 with a carriage 172 configured to couple to at leastone of the array of protrusions 120. However, the track 171 can beconfigured to couple to any other suitable element of the system 100. Inthis variation, the track(s) 171 conform to the surface of the scalp andrun parallel or antiparallel with a prevailing grain of hair growth,such that placement of the positioning module 170 at the user's scalp“combs” the array of protrusions 120 through the user's hair andfacilitate electrical coupling between the system 100 and the user. Inother variations, the positioning module 170 can be configured to coupleto the system 100 in any other suitable manner, couple to any othersuitable portion of the user's body, and guide motion of the system 100,relative to the user, along any other suitable direction.

In some variations, the positioning module 170 can be configured tocommunicate in a one-way or two-way manner with one or more electrodecontact assembly 101, 102. As such, detection that an electrode contactassembly 101, 102 was properly coupled, and identification of whichelectrode contact assembly(ies) were coupled to the electronicssubsystem 150 can be determined. In variations, communication betweenthe positioning module 170 and the electrode contact assembly(ies) 101a, 102 a, 103 a, 101 b, 102 b, can be provided by one or more of: anelectromechanical connection, an optical sensor, an identificationsensor (e.g., RFID), and any other suitable mechanism of communication.In an example, communication includes communication of the approximateshape, position, and/or area of the electrode-to-user contact regionprovided by the electrode contact assembly 101, 102 from the electrodecontact assembly 101, 102 to the positioning module 170; additionally,this information or derived information (e.g., charge density) can bepresented to the user (e.g. using a mobile device 158) or used by theelectronics subsystem 150 to prevent delivery of stimulation that wouldincrease a value such as charge density or accumulated charge densitypast a predetermined limit.

As shown in FIGS. 14A-14B, the electrode system 100 can additionallyfurther comprise a hair displacement module 180, which functions tofacilitate stimulation and/or signal recording by the system 100, byproviding access, through the user's hair, to the user's skin. The hairdisplacement module 180 preferably facilitates the displacement of hairto allow contact between the system 100 and the skin of the user, by wayof a mechanism that laterally displaces the user's hair (e.g., when theuser pushes a button, when the user turns a knob, when the user slides apost, when the user activates any other suitable input device, etc.), anexample of which is shown in FIG. 14A. The hair displacement module 180can, however, displace the user's hair in any other suitable manner. Asdescribed briefly above, one or more portions of the system 100 can beconfigured to expand outward to laterally displace hair of the user(e.g., upon absorption of fluid). In one such variation, examples ofwhich are shown in FIGS. 15A and 15B, one or more regions of a permeablebody 111 situated within a protrusion/channel of the housing 105 can beconfigured to undergo at least one of volumetric expansion (as shown inFIG. 15A) and area expansion (as shown in FIG. 15B) to promote contactbetween the system 100 and skin of the user. However, in achieving adesired contact area condition at a system-user body interface, apermeable body 111 configured for area expansion can use a significantlysmaller volume of fluid for saturation of the permeable body 111.

In deploying tip regions of the array of permeable bodies 110 forcontact with the body region of the user, the housing 105 and/or anyother suitable portion of the system 100 can be configured to transitionthe array of permeable bodies 110 from a contracted state 111 a to anextended state 111 b relative to the housing 105 (and/or any othersuitable portion of the system 100). In a first variation, as shown inFIG. 16A, the array of permeable bodies 110 can be configured to expandin place, once the system 100 is positioned on the user, in establishingcontact between the array of permeable bodies 110 and the body region ofthe user. In examples of the first variation, one of which is shown inFIG. 17, the material of the permeable bodies 110, as described above,can absorb fluid and volumetrically expand within a confined region(e.g., channel of the housing no) having an opening, such that thematerial expands outward from the opening to establish contact with thebody region of the user. Additionally or alternatively, in anotherexample of the first variation, microfluidic channels of the manifold140 can be designed to improve consistency of fluid distribution to thearray of permeable bodies 110 to promote expansion of the array ofpermeable bodies 110 in place at the user.

In a second variation, as shown in FIG. 16B, the array of permeablebodies 110 can be transitioned to the extended state 111 b, from thehousing 105, in establishing contact between the array of permeablebodies 110 and the body region of the user. In a first example of thesecond variation, as shown in FIG. 18A, a chamber 115 that is actuatablewithin a channel of the housing 105 can support a permeable body 111 ina contracted state ma, wherein the contracted state is maintained by wayof a seal (e.g., foil seal, plastic seal, paper seal, seal configured todissolve when wet, cap, etc.) coupled at a distal end of the channel. Inthe first example, the chamber 115 can include a reservoir for a volumeof fluid that saturates the permeable body, upon displacement of thechamber 115 in a distal direction to transition the permeable body tothe extended state 111 b (with breaking of the seal). In a secondexample related to the first example, as shown in FIG. 18B, the array ofpermeable bodies 110 can comprise a set of wicking elements 116configured to splay outward about a flanged portion of the housing 105upon transitioning the permeable bodies 110 from the contracted state111 a to the extended state 111 b. In a third example related to thefirst example, as shown in FIG. 18C, the chamber 115 can be substitutedwith a post 116 configured to couple with a portion of a permeable bodyin having a folded configuration, that expands outward (e.g., as in afanned configuration) upon transitioning the permeable body in from thecontracted state 111 a to the extended state 111 b. In a fourth examplerelated to the third example, as shown in FIG. 18D, the portion of apermeable body in configured to expand can have a spiral-woundconfiguration, that unwinds outward upon transitioning the permeablebody in from the contracted state 111 a to the extended state 111 b.

In a third variation, as shown in FIG. 16C, the array of permeablebodies 110 can be configured to be exposed upon retracting of one ormore portions of the housing 105, and/or elements associated with thehousing 105 in establishing contact between the array of permeablebodies 110 and the body region of the user. In examples of the thirdvariation that are analogous to the examples of the second variation, asshown in FIGS. 19A-19D, the housing 105 can be displaced relative to anobject (e.g., chamber 115, post 116) supporting a permeable body 111,thereby transitioning the permeable body from the contracted state 111 ato the extended state 111 b.

In an alternative variation, as shown in FIG. 16D, the array ofpermeable bodies 110 can be in an extended state 111 b with an abilityto undergo elastic deformation (e.g., as sprung tips), such that contactwith the body region of the user, or biasing of the array of permeablebodies 110 toward the body region of the user allows the tip regions toelastically deflect outward to enhance contact between the array ofpermeable bodies 110 and the body region of the user. In examples, asshown in FIGS. 20A-20C, a permeable body 111 having a compliant tipregion can be coupled to a valve 117 within a channel of the housing105, wherein biasing the tip region of the permeable body 11 toward thebody region of the user simultaneously displaces the valve 117 torelease a volume of fluid toward the tip region and allows the tipregion to deflect outward to enhance contact with the body region of theuser. In these examples, the tip region can interface with the housing105 in any suitable manner (e.g., the tip region can be at leastpartially seated within a channel of the housing, the tip region can becoupled to an external portion of the housing 105, etc.). Additionallyor alternatively, portions of the housing 105 in communication with apermeable body 111 can be configured to conduct current be beingcomposed of a conductive material and/or by coupling to a conductivetrace that is in communication with the electronics subsystem 160.

Any one or more of the above variations and examples can additionally oralternatively use a material with shape-memory behavior (e.g., nitinol,etc.) to drive transitioning of a permeable body 111 between acontracted state 111 a and an extended state 111 b. Furthermore, tosupport formation of an electrical interface between the system 100 andthe body region of the user, a conductive material (e.g., putty,material with non-Newtonian behavior, a material withtemperature-dependent viscosity, a memory foam saturated withelectrolyte, etc.) can be used to promote a desired level of contactbetween the system 100 and the body region of the user during use of thesystem 100. Additionally or alternatively, vibration (e.g., ultrasonicvibration, mechanical vibration) can be used by a vibration module ofthe system 100 to encourage movement of the array of permeable bodies110 through hair of the user and into position at the body region of theuser. Vibration can also be used to indicate, to the user, that properpositioning of the array of permeable bodies 110 at the body region isoccurring or has occurred.

In still alternative variations, the hair displacement module 180comprises at least one comb 181 and at least one actuator 182 (e.g.,automatic or manual actuator) that facilitates actuation of the comb 181in a direction parallel to the surface of the user's skin. In thisvariation, the comb(s) can be flexible or rigid, and can comprise anysuitable shape/configuration of protrusions. In this variation, uponapplication of the system 100 to the user, the comb(s) 181 can belaterally displaced by the actuator(s) 182, thus parting the user's hairand allowing stimulating/sensing elements of the system 100 to contactthe user's skin. In a specific example of this variation, the combs 181include protrusions that are oriented in a lateral direction, as well asprotrusions that are oriented in a direction perpendicular to the user'sskin surface, which cooperate to facilitate hair gripping and lateraldisplacement of hair. In the specific example, the combs 181 are alsoflexible to allow the combs 181 to bend upward away from the skin afterthey have been laterally displaced. In this manner, the hairdisplacement module 180 can also function to mitigate a biasing force onthe system 100 by the user's hair. Variations of the combs are shown inFIG. 14B.

Combinations of the above variations and examples can, however, beconfigured in any other suitable manner.

As shown in FIGS. 21A-21D, the electrode system 100 can additionally oralternatively further comprise a hair gripping module 190, whichfunctions to provide a biasing force between the user's scalp and thesystem 100, in order to provide robust coupling between the system 100and the user. In the orientation shown in FIGS. 21A-21D, the hairgripping module 190 preferably provides a downward force (e.g., towardthe user's scalp), and can additionally or alternatively be configuredto provide opposing lateral forces, relative to the surface of theuser's skin, thereby facilitating robust coupling between the user andthe system 100. The hair gripping module 190 can be configured at anyposition proximal a housing 105 of the system 105 or proximal any othersuitable element of the system 100.

In one variation, the hair gripping module 190 comprises at least oneelastic element 191 (e.g., spring, elastomer) configured to deform anddefine openings 192 that can receive a user's hair. The elasticelement(s) 191 is/are preferably polymeric and non-conducting, whichinhibits shorting of any current to the user during stimulation, andreduce electronic noise that interferes with any detected signals.However, the elastic element(s) 191 can be composed of any suitableconducting material (e.g., metal) or non-conducting material. In thisvariation, the elastic element(s) 191 are oriented about a periphery ofa footprint of an element of the system 100 (e.g., a housing 105 of theelectrode system 100). In a first configuration (e.g., a default state),with no force applied to the elastic element, openings 192 of theelastic element 191 are smaller than a defining dimension of the user'shair, and the user's hair is unable to be received within the openings192 of the elastic element(s) 191. In a second configuration, however, aforce applied to the elastic element(s) 191 causes a deformation in theelastic element(s) 191 that enables the openings 192 to expand andreceive the user's hair. Then, in a return to the first configuration,the user's hair is trapped within the openings 192 of the elasticelement(s) 191, in a manner that can be reversed by reapplying a forceto the elastic element(s) 191. In specific examples, the elasticelement(s) 191 can include springs with coils defining openings 192,and/or elastomeric elements with openings 192 defined within theelastomeric elements.

In an example of this variation of the hair gripping module 190, asshown in FIG. 21A, an axial force can be applied to one or more ends ofan elastic element 191, in a manner that facilitates expansion of theopenings 192 (e.g., an increase in an inter-coil distance) to adimension greater than or equal to a defining dimension (e.g., hairdiameter) of the user's hair. In this example, forces exerted by theuser's hair on a housing 105 of the system 100 enhance coupling betweenthe housing 105 of the system and the user, as facilitated by anchoringof the user's hair at the user's scalp. The axial force(s) can beenabled by at least one actuator 193, as shown in FIG. 21A, such as asolenoid motor, a DC motor, an AC motor, and/or a stepper motor.

In a second example of this variation of the hair gripping module 190,as shown in FIG. 21B, a transverse force and/or a bending force can beapplied to a portion of an elastic element 191, which produces bendingof the elastic element 191. The bending allows expansion of the openings192 of the elastic element 191 (e.g., expansion of inter-coil spacingnear an apex of bending in a spring), thereby initiating and enablinghair gripping. In this example, forces exerted by the user's hair on ahousing 105 of the system 100 enhance coupling between the system 100and the user, as facilitated by anchoring of the user's hair at theuser's scalp. Furthermore, in this example, lateral forces directed awayfrom the system 100 (e.g., in a direction parallel with the user'sscalp) can be provided that further enhance coupling between the system100 and the user. Lateral forces occur in response to straightening of abent elastic element, which reduces an opening dimension (e.g., aninter-coil distance) below hair-width before the elastic element hasfully returned to a straightened state. In this manner, the user's hairis gripped by the elastic element(s) and then pulled along with theelastic element(s) 191 during straightening of the elastic element(s)191. Thus, elastic elements located at opposing sides of a housing 105of the system 100 can be configured to provide lateral forces directedaway from the system 100, thereby maintaining a position of theelectrode system 100 on the surface of the scalp.

In the second example of this variation of the hair gripping module 190,the transverse/bending force can be applied to the end(s) of an elasticelement 191 by any one or more of: of a sliding mechanism, as shown inFIG. 21B, a force provided in an out-of-plane direction to a planedefined by the elastic element(s) 191, as shown in FIG. 21C, and by wayof a torsional mechanism, as shown in FIG. 13D. In the examples shown inFIGS. 21C-21D, out-of plane forces and/or torsional forces can beapplied to one or more elastic elements 191 arranged about a peripheryof a footprint of the housing 105 of the system 100, by way of couplers(e.g., filament, fiber, string, wire, flexible coupler, rigid coupler)coupling the elastic element(s) 191 to at least one actuator 193providing the out-of-plane/torsional force. The actuator 193 in theseexamples can include a solenoid motor, a DC motor, an AC motor, astepper motor, and/or any other suitable actuator, and can be coupled toa pulley subsystem or any other suitable subsystem configured totransmit the out-of-plane and/or torsional force(s).

The system 100 can, however, comprise any other suitable element(s) orcombination of elements that enable displacement of a user's hair and/orenhance coupling between the electrode system 100 and the user.

The system 100 and method of the preferred embodiment and variationsthereof can be embodied and/or implemented at least in part as a machineconfigured to receive a computer-readable medium storingcomputer-readable instructions. The instructions are preferably executedby computer-executable components preferably integrated with the system100 and one or more portions of the processor and/or a controller. Thecomputer-readable medium can be stored on any suitable computer-readablemedia such as RAMs, ROMs, flash memory, EEPROMs, optical devices (CD orDVD), hard drives, floppy drives, or any suitable device. Thecomputer-executable component is preferably a general or applicationspecific processor, but any suitable dedicated hardware orhardware/firmware combination device can alternatively or additionallyexecute the instructions.

The FIGURES illustrate the architecture, functionality and operation ofpossible implementations of systems, methods and computer programproducts according to preferred embodiments, example configurations, andvariations thereof. In this regard, each block in the flowchart or blockdiagrams may represent a module, segment, or portion of code, whichcomprises one or more executable instructions for implementing thespecified logical function(s). It should also be noted that, in somealternative implementations, the functions noted in the block can occurout of the order noted in the FIGURES. For example, two blocks shown insuccession may, in fact, be executed substantially concurrently, or theblocks may sometimes be executed in the reverse order, depending uponthe functionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts, or combinations of special purpose hardware andcomputer instructions.

As a person skilled in the field of biosignals or neurostimulation willrecognize from the previous detailed description and from the figuresand claims, modifications and changes can be made to the preferredembodiments of the invention without departing from the scope of thisinvention defined in the following claims.

We claim:
 1. A system for electrically stimulating a user, the systemcomprising: an array of permeable bodies that facilitates electricalcoupling between the system and a body region of the user during use,wherein each of the array of permeable bodies has a cavity at a proximalportion and a tapered distal portion, is configured to transmit anelectrolyte solution, through hair of the user, to the body region ofthe user during use and is composed of an olefin polymer thatelastically deforms upon interfacing with the body region of the user; asubstrate region defining an array of protrusions corresponding to andconfigured to reside within cavities of the array of permeable bodies,the substrate region composed of a conductive material; and a set ofconductors in communication with the substrate region, the set ofconductors configured to couple to an electronics subsystem fortransmission of current through the set of conductors and the array ofpermeable bodies for electrically stimulating the user during use of thesystem.
 2. The system of claim 1, further comprising a first housingportion defining an array of openings at a broad surface, wherein distalportions of the array of permeable bodies are exposed through the arrayof openings of the first housing portion.
 3. The system of claim 2,further comprising a second housing portion coupled to the first housingportion, the first and second housing portions defining a volume withinwhich the substrate region and the set of conductors are sealed, andwherein at least one of the first housing portion and the second housingportion includes a ferromagnetic material region that interfaces thesystem with a magnet of an external headset that couples the system tothe user.
 4. The system of claim 2, wherein a base region of eachopening of the array of openings of the first housing portion isrecessed at the broad surface, such that the base region of each openingdefines a bowl about its corresponding opening.
 5. The system of claim1, wherein each of the array of permeable bodies is impregnated with anelectrolyte component and configured to be saturated with fluid, therebygenerating the electrolyte solution from fluid combined with theelectrolyte component, prior to use by the user.
 6. The system of claim1, further comprising an electromechanical coupler configured to couplethe set of conductors to an electronics subsystem for transmission ofcurrent through the set of conductors and to the array of permeablebodies.
 7. The system of claim 6, wherein the electromechanical couplerincludes an electronics substrate having a detection connector coupledthrough a resistor, having a characteristic value, to a stimulationconnector, wherein the electronics substrate is configured to reversiblyinterface with a detection circuit, of the electronics subsystem, thatprovides a probe voltage to the stimulation connector, thereby producinga characteristic voltage at the detection connector that is determinedby the detection circuit.
 8. The system of claim 7, wherein thecharacteristic voltage is indicative of a specific electrode unit of thesystem, and wherein electronics subsystem is configured generate analert output upon detection that the characteristic voltage correspondsto an electrode unit system configuration unsuitable for use by theuser.
 9. The system of claim 1, wherein the set of conductors includes afirst conductor configured to provide a first subset of the array ofpermeable bodies with a first polarity and a second conductor configuredto provide a second subset of the array of permeable bodies with asecond polarity.
 10. The system of claim 9, wherein the substrate regioncomprises a first subregion coupled to the first subset of the array ofpermeable bodies and a second subregion coupled to the second subset ofthe array of permeable bodies, wherein the first subregion of thesubstrate region is separated from the second subregion of the substrateregion by an insulator.
 11. The system of claim 1, wherein the secondconductor of the set of conductors is configured to provide both thesecond subset and a third subset of the array of permeable bodies withthe second polarity, wherein the first subset of the array of permeablebodies forms a first rectangular subarray, the second subset forms asecond rectangular subarray adjacent a first side of the firstrectangular subarray, and the third subset forms a third rectangularsubarray adjacent a second side of the first rectangular subarray.
 12. Asystem for electrically stimulating a user, the system comprising: anarray of permeable bodies that facilitates electrical coupling betweenthe system and a body region of the user during use, wherein each of thearray of permeable bodies has a cavity, is composed of a polymer thatelastically deforms upon interfacing with the body region of the user,and is configured to transmit an electrolyte solution to the body regionof the user during use; a substrate region defining an array ofprotrusions corresponding to and configured to reside within cavities ofthe array of permeable bodies, the substrate region composed of aconductive material; and a set of conductors in communication with thesubstrate region, the set of conductors configured to couple to anelectronics subsystem for transmission of current through the set ofconductors and the array of permeable bodies.
 13. The system of claim12, further comprising a first housing portion defining an array ofopenings at a broad surface, wherein each of the array of permeablebodies has a tapered distal portion exposed through the array ofopenings of the first housing portion.
 14. The system of claim 13,wherein a base region of each opening of the array of openings of thefirst housing portion is recessed at the broad surface, such that thebase region of each opening defines a bowl about its correspondingopening.
 15. The system of claim 12, wherein each of the array ofpermeable bodies is composed of an olefin polymer foam.
 16. The systemof claim 12, wherein the substrate region comprises a first subregioncoupled to a first subset of the array of permeable bodies and a secondsubregion coupled to a second subset of the array of permeable bodies,wherein the first subregion of the substrate region is separated fromthe second subregion of the substrate region by an insulator.
 17. Thesystem of claim 12, wherein each of the array of permeable bodies isimpregnated with a dried electrolyte component, and configured to besaturated with fluid prior to use by the user in forming an electricallyconductive interface with the user.
 18. The system of claim 12, whereinthe set of conductors comprises a first conductor configured to providea first subset of the array of permeable bodies with a first polarityand a second conductor configured to provide both a second subset and athird subset of the array of permeable bodies with a second polarity.19. The system of claim 18, wherein the first subset forms a firstrectangular subarray, the second subset forms a second rectangularsubarray adjacent a first side of the first rectangular subarray, andthe third subset forms a third rectangular subarray adjacent a secondside of the first rectangular subarray.
 20. The system of claim 12,further comprising a housing defining a volume within which thesubstrate region and the set of conductors are sealed, and wherein thehousing includes a ferromagnetic material region that interfaces thesystem with a magnet of an external headset that couples the system tothe user.